OLIMEX AgonLight2 User manual

AgonLight2
User Manual
Rev.1.1 January 2023
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olimex.com
Table of Contents
Introduction................................................................................................................................................3
What is AgonLight2?.............................................................................................................................4
AgonLight references documents:.........................................................................................................5
The difference between AgonLight and AgonLight2:...........................................................................
Order codes for AgonLight2 and accessories:.......................................................................................7
HARDWARE.............................................................................................................................................8
AgonLight2 layout:...............................................................................................................................9
AgonLight2 schematic:.......................................................................................................................10
AgonLight2 power supply and consumption:.....................................................................................15
GPIO connector:..................................................................................................................................1
UEXT connector:.................................................................................................................................18
Access bus connector:.........................................................................................................................19
eZ80 programming connector:............................................................................................................20
Jumpers:...............................................................................................................................................21
SOFTWARE:...........................................................................................................................................22
AgonLight2 Firmware.........................................................................................................................23
How to prepare the SD card and boot the first time............................................................................23
MOS commands:.................................................................................................................................24
LOAD “”.............................................................................................................................................24
BBC Basic commands reference:........................................................................................................25
Software access to GPIOs:..................................................................................................................2
Software access to I2C:.......................................................................................................................27
Software access to SPI:.......................................................................................................................28
Software access to VPU:.....................................................................................................................29
Revision History......................................................................................................................................30
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Introduction
3

What is AgonLight2?
AgonLight2 is re-design of the original AgonLight eZ80F92 retro computer, designed as hobby project
by Bernardo Kastrup.
AgonLight2 is complete Single Board Computer with VGA display output, PS2 keyboard and SD card
(acting as external Disk), so to write programs and run them you do not need external computer like
Arduino does.
AgonLight has GPIO connector with GPIO ports, I2C, SPI etc signals which are accessable and can be
used to interact with other hardware, sensors etc.
AgonLight and AgonLight2 are Open Source Hardware and officially OSHWA certified.
All CAD source files are available at AgonLight and AgonLight2 GitHub repositories. They are
released under CERN Open Hardware Licence Version 2 - Strongly Reciprocal and allow users to
learn, study, edit, modify, produce and sell same or derivative products based on these designs. The
only requirements is to open source their work under the same licensee.
The firmware of AgonLight is written by Dean Belfield and reproduces BBC Basic for Z80. The
firmware is also Open Source Software and available on GitHub. The same firmware works on
AgonLight2 without any modifications.
AgonLight2 is RoHS, REACH, CE and UKCA compliant.
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AgonLight references documents:
Here we link original AgonLight Hardware Manual, QuickStart Guide and Firmware Installation
Guide.
Note that AgonLight2 will come to you completely assembled, tested and with programmed firmware,
so you can use the above documents just for reference and completeness.
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The difference between AgonLight and AgonLight2:
AgonLight2 has these differences from the original design:
•KiCadis used as CAD instead of EasyEDA. KiCad is open source software free to download
and use more proper for Open Source Hardware project;
•USB-C connector for power supply;
•DCDC power converter with up to 2A output instead of linear power converter;
•LiPo battery backup power supply, the battery act like UPS and will power the computer even if
the external power supply on USB-C connector is removed. The battery is charged
automatically when external power supply is available;
•USB connector for keyboard (the keyboard must be PS2 compatible!!!);
•SRAM is routed with 40 ohm impedance as per part datasheet;
•Fixed some wrong signal naming on ESP32-PICO-D4 GPU co-processor;
•Fixed GPIO and Programming connector pin ordering;
•Replaced the nacked header 32-pin connector with a plastic boxed 34-pin connector following
the same layout and adding two additional signals Vbat and Vin which allow AgonLight2 to be
powered by this connector too.
•Added a UEXT connector (https://www.olimex.com/Products/Modules/) which allows
AgonLight2 to be connected to: temperature sensors, environmental air quality sensors,
pressure, humidity, gyroscope, light, RS485, LCDs, LED matrix, relays, Bluettooth, Zigbee,
Lora, GSM, RFID reader, GPS, Pulse, EKG, RTC etc;
•Added 4 grounded mount holes with 3mm diameter, but kept the original 2.5 mm mount holes;

Order codes for AgonLight2 and accessories:
AgonLight2 - Single Board BBC Basic Z80 Retro style Computer
AgonLight2-BOX - Metal box for AgonLight2
CABLE-USB-A-C-1M - USB-C power cable
BATTERY-LIPO1400mAh - Lipo battery 3.7V 1400mAh – note these batteries can be shipped only
by ground so we can deliver only to EU
destinations.
USB-KEYBOARD-PS2 - USB keyboard which supports PS2 and can be used for
AgonLight2
B READBOARD-1 - Breadboard for experimenting with AgonLight2
JW-200x10-FM - 10 pcs Female/Male Jumper Wires for breadboarding
JW-200x10 - 10 pcs Male/Male Jumper Wires for breadboarding
JW-200x10-FF - 10 pcs Female/Female Jumper Wires for breadboarding
UEXT modules - different sensors, relays, LCDs, RTC, GSM, GPS etc
accessories which can be connected to AgonLight2
UEXT connector
MOD-Wii-UEXT-NUNCHUCK - 3 axes joystick, 3 axes accelerometer, two buttons game
controller
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HAR WARE
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AgonLight2 layout:
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Micro SD card USB-PS2 keyboard
Buzzer
LiPo battery UEXT GPIO
ESP32 programming
ESP32 UART disable
Buzzer enable
EZ80 programming
Access bus
Audio Out
VGA USB-C Power Reset

AgonLight2 schematic:
The current AgonLight2 schemaitc is available for download and print on GuitHub
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AgonLight2 power supply and consumption:
AgonLight2 can be powered by 3 sources:
•USB-C connector
•LiPo battery
•GPIO.pin2 (5V_USB) note that this signal is connected to USB 5V signal so when you power
AgonLight2 with this pin you should not connect it to the USB!!!
Power consumption of AgonLight2 is approx 130mA without and 180mA with connected keyboard.
If LiPo battery is connected it’s charged automatically when power supply is attached with about
100mA.
When the LiPo battery is attached and external power supply is missing internal DCDC step-up
converter and switching circuit automatically powers AgonLight2 from the battery. 1400mAh battery
will provide about 8 hours of stand alone operation.
+The LiPo battery connector is JST 2.0 mm connector and with Olimex’s battery polarity. If you
use batteries from other manufacturers please make PLUS and MINUS are connected properly as you
may damage the board!!!
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GPIO connector:
Pin.1 is connected to the LiPo battery PLUS you can connect external battery on this pin or to use
battery voltage to external circuits.
Pin. 2 is 5V power supply connected to USB-C +5V signal, you can power the board from this signal if
the USB-C is not connected. It must be regulated 5V power supply, applying more than 5V will
damage the board.
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Pin.3, Pin.5, Pin.33 are GND
Pin.34 is +3.3V output capable to source up to 2A note that 200mA are used by AgonLight2
Pin.4 is +5V output capable to source up to 2A (1.8A + AgonLight2 0.2A), it’s backed by LiPo UPS so
even if there is interruption on power supply if LiPo battery is attached there will be 5V on this pin.
All GPIOs are operating on +3.3V. This means you should not connect signals above 3.3V on these
ports as this will damage the board.
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UEXT connector:
UEXT connector stands for Universal EXTension connector and contain +3.3V, GND, I2C, SPI, UART
signals:
UEXT is 0.1” 2.54mm step boxed plastic connector. All signals are with 3.3V levels.
Olimex has developed number of MODULES with this connector. There are temperature, humidity,
pressure, magnetic field, light sensors. Modules with LCDs, LED matrix, Relays, Bluetooth, Zigbee,
WiFi, GSM, GPS, RFID, RTC, EKG etc.
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Access bus connector:
This is I2C and power supply with 3.3V levels.
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eZ80 programming connector:
This connector is used for initial programming of eZ80 microcontroller. AgonLight2 comes with pre-
programmed firmware so you do not need to use this connector nor programmer for it.
If you want to develop your own firmware Jeroen Venema wrote flash utility which allows you to flash
new firmware without need of external porgrammer.
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