Renesas EK-RE01 256KB Installation and operating instructions

Application Note
R01AN5406EJ0100 Rev.1.00 Page 1 of 16
Aug. 25, 2020
Energy Harvesting Launch Operation Demo using Quick
Start Mode Enabling Effective MCU Utilization during
Charging Time for RE01 256KB Group
Summary
This application note provides sample code to demonstrate energy harvesting and RE01 Family's unique
quick-start mode using the EK-RE01 256KB (Evaluation Kit RE01 256KB), a development kit for the RE01
256KB Group.
In this sample code, power is supplied from an energy harvesting control circuit (EHC) powered by an energy
harvesting element (solar panel/thermoelectric generator). By using the power generated by EHC, the MCU
is able to maintain continuous MIP LCD (SMIP) operation.
The device also has a quick start function that is unique to the EHC circuit. This function enables the
operation before the secondary battery is fully charged. In this demo, SMIP display is started during the quick
start period.
Please refer to the project included in the package for the sample code.
Target Device
RE01 256KB Group
Note
When applying the sample code covered in this application note to another microcomputer, modify the code
according to the specifications for the target microcomputer and conduct an extensive evaluation of the
modified program.
Related Document
RE01 1500KB, 256KB Group Getting Started Guide to Development Using CMSIS Package (R01AN4660).

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 2 of 16
Aug. 25, 2020
Contents
1. What is Quick Start for Energy Harvesting Circuit for RE Family?............................................3
2. Specifications ..........................................................................................................................3
2.1 Description of Project .............................................................................................................................. 3
2.2 Overview.................................................................................................................................................. 3
2.3 Pins Used ................................................................................................................................................ 5
2.4 Procedure for Operating Sample Code ................................................................................................... 6
2.5 Jumper settings and power generator element connections .................................................................. 7
3. Conditions for Checking Operation ..........................................................................................9
4. Description of Software..........................................................................................................10
5. Specifications of Driver APIs..................................................................................................12
6. Usage Notes..........................................................................................................................12
6.1 VCOM and SCS pin for MIP LCD.......................................................................................................... 12
6.2 DMAC Interrupts.................................................................................................................................... 12
6.3 Setting DMAC Transfer Source and Transfer Destination Addresses .................................................. 13
7. Troubleshooting.....................................................................................................................14
7.1 Occurrence of Build Error...................................................................................................................... 14
7.2 Occurrence of HardFault Error when API of CMSIS Driver Is Called ................................................... 14
7.3 Peripheral Function Fails to Operate when API Is Called ..................................................................... 14
7.4 Normal API Return Value But No Pin Output from Peripheral Function ............................................... 14
7.5 Peripheral Function’s Input or Output Does Not Operate as Expected ................................................ 14
8. Sample Code.........................................................................................................................14
9. Reference Documents ...........................................................................................................15
Revision History ............................................................................................................................16

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 3 of 16
Aug. 25, 2020
1. What is Quick Start for Energy Harvesting Circuit for RE Family?
Quick start is a function that is unique to EHC circuit in RE Family. This function enables the users to
immediately use the device before the secondary battery is fully charged.
Quick start mode is especially useful when secondary battery is used together with EHC circuit. Depending on
the battery size, secondary battery charging from solar cell or other energy harvesting elements may take up
to several days. This function enables the users to skip this waiting time and to use the device as soon as the
power generated by the power generating element is available.
During the battery charging period, the product can also be easily mistaken as a broken product because the
users cannot see the status of the charging. By using quick start mode, the MCU can notify the users about
the status of the charging. In this demo, the status of the secondary battery charging is shown in SMIP during
the quick start period. The timing of the quick start mode is described in Figure 1.1.
Figure 1.1 Quick Start Timing
2. Specifications
2.1 Description of Project
A sample code project "r01an5406_re_ehc_quickstart_smip.zip" is delivered with this application note.
r01an5406_re_ehc_quickstart_smip.zip is a project which operation has been confirmed on the Evaluation Kit
RE01 256KB Board. This project is configured to match the settings of RE01 256KB (R7F0E01182CFP)
mounted on the Evaluation Kit RE01 256KB Board. When using another RE01 256KB device, change the
device settings in the project to those of the target device.
2.2 Overview
By using this sample code, the board can be powered up by an energy harvester (solar panel/thermoelectric
generator. The program will send image data to SMIP display, depending on the status of secondary battery
charging progress:
While waiting for the secondary battery to finish charging, the program sends image data to SMIP. The
images used while waiting for secondary battery charging are shown in Figure 2.1.

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 4 of 16
Aug. 25, 2020
(a) during charging in quick start mode
(b) after charging is completed
Figure 2.1 SMIP Display during Quick Start Up Sequence
After the secondary battery is charged, the program goes to main.c and SMIP alternately shows the
original image and color-inverted image. The images are shown in Figure 2.2.
(a) Original Image
(b) Color-inverted Image
Figure 2.2 RE Logo in SMIP Display
The overview of the functions used in this program is shown below.

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 5 of 16
Aug. 25, 2020
Figure 2.3 Program Overview
2.3 Pins Used
The pins used by the sample code are shown below.
Pin Used
Purpose of Use
P010
MOSIA_B (SPI)
P011
RSPCKA_B (SPI)
P015
SCS (SPI)
P813
RESET (SPI)
P814
VCOM (SPI)
PMOD1
DMAC
CPU
RE01
AGT1
SOS C
32.768 kHz
In ter rup t r eq uest
MOCO
2 MHz
P814
P813
P015
MIP LCD
VCOM
RESET
SCS
EHC
GDT
Input
OutputDMAC2
DMAC1
SPI
AGT0
In ter rup t r eq uest
DMAC0
P011
P010
RSPCK
MOSI
*LOCO is oscillating during EHC startup
Power generating elements
Solar panel Thermoelectric generator
OR

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 6 of 16
Aug. 25, 2020
2.4 Procedure for Operating Sample Code
Follow the steps described below to operate the sample code. Refer to the startup guide for more details of
how to build and download the program.
1. Build the sample code
2. Follow the board setting shown in Figure 2.4 before downloading the program *1
3. Connect the debugger and download the program to the MCU.
4. Disconnect the debugger.
5. Change the board setting before operating in energy harvesting mode *1
In this sample code, users can select either a solar panel or thermoelectric generator harvester as the
power generation element.
a. When using solar panel
Evaluation Kit RE01 256KB Board and a solar panel are required. Connect the required
components by following the setting shown in Figure 2.5.
b. When using thermoelectric generator harvester
Evaluation Kit RE01 256KB Board, thermoelectric generator harvester (sold separately), and
MERCURY Eval Board (sold separately) are required. Connect the required components by
following the setting shown in Figure 2.6
6. Start EHC operation
Sample program will start when power is supplied to the VSC_VCC pin from the power generation
elements.
7. Restarting EHC operation
After the charging of the secondary battery is completed, the program transitions to a steady-state
operation period and continuously inverse the image shown in the SMIP display. If the power supply to
the MCU is interrupted and the secondary battery does not have enough voltage to maintain operation,
the operation of the MCU is intentionally stopped. The MCU can automatically restart as soon as the
power from the power generation elements is re-supplied to the VSC_VCC pin. *2
Note: *1 The board setting and connection during program download, energy harvesting mode operation with
solar panel, and energy harvesting mode operation with thermoelectric generator harvester are
different. Be sure to follow the board setting described for each respective mode.
*2 The EHC circuit starts initial operation when there is a voltage difference between the VCC and
VCC/IOVCC pins. Therefore, if the discharging process of the charge on the VCC/IOVCC pins takes
a long time due to components connected to the VCC/IOVCC pins, etc., it is not possible to create a
voltage difference to start the initial operation of the EHC circuit. For this reason, design the circuit so
that the VCC/IOVCC pins are quickly discharged. The evaluation kit has a discharge switch (SW7 of
the RE01 256KB) that can be used manually for quick discharge at the prototype stage.

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 7 of 16
Aug. 25, 2020
Do not connect
to PC
×
SW9 : MD 1
-
2 short
SW10:
EHMD
1
-
2 short
J15: 2
-
3 short
J6:
2
-
3 short
Power Generating
Element
( Solar Panel )
PMOD1: Connect to MIP LCD
-
J8: 2
-
3 short
SW3: EHC
SW4: EHC
SW5: EHC
SW6: EHC
J10:
1
-
2 open
2
-
3 open
J9: short
T10: + pole
T9: - pole
2.5 Jumper settings and power generator element connections
・Fig. 2.4 shows the board setting when downloading the program.
・Fig. 2.5 shows the board setting during energy harvesting operation (using solar panel)
・Fig. 2.6 shows the board setting during energy harvesting operation (using thermoelectric generator
harvester)
Figure 2.4 Board setting when downloading the program
Figure 2.5 Board setting during energy harvesting operation (using solar panel)

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 8 of 16
Aug. 25, 2020
Figure 2.6 Board settings during energy harvesting operation (using thermoelectric generator
harvester)
This sample code can use a thermoelectric generator as a power generation element. A thermoelectric
generator is a device that uses temperature difference to generate electricity. In this demo, the power is
harvested from the temperature difference between human body and room temperature. To power up the
MCU, place a finger to the thermoelectric generator harvester.
To run the demonstration, connect the MERCURY Eval Board, thermoelectric generator harvester, and
Evaluation Kit RE01 256KB Board as shown in Figure. 2.6. Thermoelectric generator harvester harvests the
power generated from temperature difference between human body and room temperature. MERCURY Eval
Board is used to increase the voltage generated by the thermoelectric generator harvester to a level that can
support Evaluation Kit RE01 256KB Board operation.
Caution: Always check the electrical polarity of the cables when connecting the thermoelectric generator
harvester to MERCURY Eval Board. In the device used this demonstration (GEM-H071010), the
red wire is the negative pole and the black wire is the positive pole. Make sure to connect the
components according to its respective correct electrical pole.
Do not connect
to PC
×
SW9 : MD 1
-
2 short
SW10:
EHMD
1
-
2 short
J15: 2
-
3 short
J6:
2
-
3 short
-
J8: 2
-
3 short
SW3: EHC
SW4: EHC
SW5: EHC
SW6: EHC
J10:
1
-
2 open
2
-
3 open
J9: short
MERCURY Eval Board
(MCRY-EVALKIT)
Thermoelectric Generator Harvester
(GEM-H071010)
T10: + pole
T9: - pole
Caution:
Always check the electrical
polarity of this device
JP4
JP5
JP7
JP6

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 9 of 16
Aug. 25, 2020
3. Conditions for Checking Operation
The operation of the sample code delivered with this application note has been checked under the following
conditions (Table 3-1).
Table 3-1 Conditions for Checking Operation
Item
Description
Microcontroller used
R7F0E01182CFP (RE01 256KB Group)
Operating frequency
ICLK: MOCO 2 MHz
PCLKB: MOCO 2MHz
Operating voltage
•3.3 V
Target board
Evaluation Kit RE01 256KB Board
Display
SMIP display (RTK70E015DB00000BE) *Included in the
Evaluation Kit
Solar energy harvester
Solar Panel (AM-1815CA) *Included in the Evaluation Kit
Thermoelectric generator harvester
Thermoelectric generation element (GEM-H071010)
MERCURY Eval Board (MCRY-EVALKIT)
Development
environment
GCC
e2studio 2020-07 made by Renesas Electronics
IAR
IAR Embedded Workbench for ARM Version 8.40.2.22891
C compiler
GCC
GCC ARM Embedded V6.3.1.20170620
GNU 6-2017-q2-update
IAR
IARC/C++ Compiler for ARM Version 8.40.2 or later
Version of I/O header
Rev. 1.00
Version of CMSIS driver package
Rev. 1.00

Energy Harvesting Launch Operation Demo using Quick Start Mode Enabling Effective
MCU Utilization during Charging Time for RE01 256KB Group
R01AN5406EJ0100 Rev.1.00 Page 10 of 16
Aug. 25, 2020
4. Description of Software
This sample code demonstrates EHC quick start up and operation powered by a solar panel. In EH mode,
users can choose to connect 2.4 V, 2.5 V, 2.6 V, 2.7 V, 2.8 V, 2.9 V, 3.0 V, and 3.1 V secondary battery or
super capacitor. Figure 4.1 shows the timing chart of this sample code when using 3.1 V secondary battery.
EH also has an overcharge protection circuit to prevent overcharging of the secondary battery connected to
the VBAT_EHC pin and the storage capacitor connected to the VCC_SU pin by the power generating element
connected to the VSC_VCC pin. In this sample code, the threshold voltage for charging protection of VBAT is
3.070 V (when 3.1 V VBAT charging voltage is used).
Figure 4.1 Timing Chart for EHC Operation (using 3.1 V secondary battery)
The sample code performs the following operations.
- When solar panel is connected to the board, the secondary battery charging period starts. During
secondary battery charging period, SMIP shows the status of the charging (Figure 2.1).
- After secondary battery charging is finished, the program goes to main file and sends image data to SMIP.
The display is toggled between original image and color-inverted image (Figure 2.2)
Figure 4.2 shows the program flow during the secondary battery charging period. Figure 4.3 shows the program
flow after going to main (after secondary battery charging period ends).
3.1 V
0 V
2.33 V
1.67 V
CPU
EH State
LCD Image
LVDBAT
Detection Level
LVD1
Detection Level 1.67 V
2.33 V
Energy Harvesting PG
(VSC pin)
VCC_SU
(Power Storage
Capacitor)
VCC
(Internal MCU)
VBAT_EHC pin
(Battery)
LVDBAT Interrupt
LVD1 Interrupt
OFF SSTBY
Providing Power
Charging battery
Quick Start
LVDBAT Interrupt
Steady operation
period
Not providing power
SSTBY Active SSTBY Active OFF
Active SSTBY
LVD1 Interrupt
Intermittent Operation
Operation
stopped
AGT1
interrupt
AGT1
interrupt
Power On
Reset
Quick Start
Providing Power
Acti
ve
Charging
battery
SSTB
Y
Active SSTBY
LVDBAT
Interrupt
Steady
operation
period
Reset release Reset release
2.60V
VCC_SU_H
*2
Activ
e
Notes:
*1
V
batc
: Secondary battery (VBAT) Charging Voltage
*2
VCC_SU_H: Startup threshold voltage at the time of starting up the energy harvest mode
*3
V
detBAT
: Voltage detection level for LVDBAT (voltage monitoring BAT) circuit
*4
V
det
: Voltage detection level for LVD1 (voltage monitoring 1) circuit
*5
V
POR
: Voltage detection level for power-on reset circuit
1.50 V
Reset Rese
t
AGT1
interrupt
V
POR
*5
V
det
*4
V
detBAT
*3
V
batc
*1
Not charging
(using power from battery)