OLIMEX AgonLight2 User manual

AgonLight2
User Manual
Rev.1.8 October 2023 olimex.com
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Table of Contents
INTRODUCTION...............................................................................................................................................3
What is AgonLight2?......................................................................................................................................4
Order codes and lin s for AgonLight2 and accessories..................................................................................5
The differences between AgonLight and AgonLight2....................................................................................6
First time start up or how to prepare the SD card and boot............................................................................7
AgonLight reference documents:....................................................................................................................7
HARDWARE.......................................................................................................................................................8
AgonLight2 layout..........................................................................................................................................9
AgonLight2 schematic..................................................................................................................................10
AgonLight2 dimensions................................................................................................................................10
AgonLight2 power supply and consumption................................................................................................15
GPIO connector............................................................................................................................................16
UEXT connector...........................................................................................................................................17
Access bus connector....................................................................................................................................18
eZ80 programming connector.......................................................................................................................19
Jumpers.........................................................................................................................................................20
SOFTWARE......................................................................................................................................................21
Official AgonLight Firmware.......................................................................................................................22
Extra info about AgonLight2 firmware:.......................................................................................................22
BASIC and demo installation.......................................................................................................................23
Agon Quar VDP installation..................................................................................................................23
Agon Quar MOS installation on the eZ80 chip.....................................................................................24
Olimex tested firmware and examples..........................................................................................................25
MOS commands...........................................................................................................................................26
BBC Basic commands reference..................................................................................................................27
Software access to GPIOs.............................................................................................................................28
Software access to I2C..................................................................................................................................29
Software access to SPI..................................................................................................................................30
Software access to VPU................................................................................................................................31
DOCUMENT REVISION.................................................................................................................................32
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INTRODUCTION
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What is AgonLight2?
AgonLight2 is a re-design of the original AgonLight eZ80F92 retro computer, designed as a hobby project by
Bernardo Kastrup;
AgonLight2 is a complete Single Board Computer (SBC) with VGA display output, PS2 eyboard, and SD
card (acting as an external dis ). This means that to write and run programs you do not need an external
computer li e Arduino boards do;
AgonLight2 is BASIC-programmable microcomputer;
AgonLigh t2 has a GPIO connector with GPIO ports, I2C, SPI, and more signals, which are accessible and
can be used to interact with additional hardware (sensors, expansions, 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 License 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 wor 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 wor s on AgonLight2 without any
modifications.
AgonLight2 is RoHS, REACH, CE and UKCA compliant.
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Order codes and links for AgonLight2 and accessories
AgonLight2 Single board BBC BASIC Z80 Retro style computer
MICRO-SD-CLASS You need a microSD card to store BASIC and software (demos,
examples)
AgonLight2-Proto DIY expansion it with big proto area; compatible with AgonLight2
BOX-AGONLIGHT2-BLACK Protective metal boxwith polymer coating; compatible with AgonLight2
CABLE-USB-A-C-1M USB-C data and power cable
BATTERY-LIPO1400mAh Li-po battery 3.7V 1400mAh – note that these batteries can be shipped
only by ground so we can deliver only to EU destinations
USB-KEYBOARD-PS2 USB eyboard which supports PS2 and can be used for AgonLight2
B READBOARD-1 Breadboard for experimenting with AgonLight2
JW-200x10-FM 10 pieces female-male jumper wires for breadboarding
JW-200x10 10 pieces male-male jumper wires for breadboarding
JW-200x10-FF 10 pieces 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 axis joystic , two buttons game controller with UEXT connector
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The differences between AgonLight and AgonLight2
AgonLight2 has these differences from the original design:
•KiCad is used for the CAD, instead of EasyEDA. KiCad is open source software – free to download
and use, it is a more fitting CAD tool for an Open Source Hardware project;
•USB-C connector for power supply;
•DCDC power converter with up to 2A output instead of linear power converter;
•Li-Po battery bac up power supply, the battery acts li e a UPS and will power the computer even if
the USB-C gets disconnected. The battery is charged automatically when USB or external power
supply is present;
•USB connector for eyboard (but the eyboard must be PS2 compatible!!!);
•SRAM 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 na ed 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 UEXT connector – it allows AgonLight to be expanded easily (without soldering) with:
temperature sensors, environmental air quality sensors, pressure sensors, humidity sensors,
gyroscopes, light sensors, RS485, LCDs, LED matrices, relays, Bluetooth modules, Zigbee modules,
Lora modules, GSM modules, RFID readers, GPS, pulse, EKG, RTC, etc;
•Added 4 grounded mount holes with 3.3mm diameter, but also ept the original 2.5 mm mount holes.
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irst time start up or how to prepare the SD card and boot
Important! Notice that AgonLight2 comes completely assembled, tested, and programmed with firmware.
The only thing you would need to do is prepare a microS card with BBC basic and some examples, then
connect your display and peripherals and apply power supply. The board comes without micro S card
which has to be purchased separately! You might need extra S card writer.
1. Open a web browser and navigate to: https://github.com/OLIMEX/AgonLight2
2. Clic on: “Code” → Download ZIP (in “Local” tab);
3. Extract the downloaded ZIP file in your PC;
4. Enter the folders “SOFTWARE” and then “1-SD-card-contents”, then copy the contents of the folder;
5. Attach a class-10 micro SD card to your PC (formatted in FAT32 and with a size of maximum 32GB);
6. Paste the contents of the folder “1-SD-card-contents” which you’ve copied in step 4, to the microSD card.
Files should be placed directly into main folder of the card;
7. Eject the micro SD card from your PC;
8. Insert the micro SD card into the AgonLight2 board;
9. Connect a VGA monitor and a PS/2 eyboard (or a PS/2-compatible USB eyboard,
via a PS/2 adapter) to the AgonLight2 unit;
10. Turn the AgonLight2 board on by connecting it to the USB cable.
More detailed info about the software can be found further below in the document.
AgonLight reference documents:
Lin s to original AgonLight manuals: AgonLight Hardware Manual, Quic Start Guide, and Firmware
Installation Guide.
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HARDWARE
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AgonLight2 layout
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Micro SD card USB-PS2 eyboard
Buzzer
LiPo battery UEXT GPIO
connector
ESP32 programming
jumper
ESP32 UART disable
jumper
Buzzer enable
jumper
EZ80 programming
Access bus
Audio Out VGA USB-C power
Reset button

AgonLight2 schematic
The current AgonLight2 design is available for download and print at GitHub – there is PDF export of the
schematic, all sources, 3D view files, gerbers, bill-of-materials and more.
AgonLight2 dimensions
Dimensions can be found in this document:
https://github.com/OLIMEX/AgonLight2/blob/main/DOCUMENTATION/AgonLight2-dimensions-mm.pdf
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AgonLight2 power supply and consumption
AgonLight2 can be powered by 3 sources:
•USB-C connector;
•Li-Po battery connector;
•GPIO.pin2 (5V_USB) note that this wire is connected to the 5V of the USB so when you power
AgonLight2 from GPIO.pin2 – you should not connect have USB cable attached at the same time!!!
The power consumption of AgonLight2 is approximately 130mA without a eyboard and around 180mA
with a eyboard connected.
If a Li-Po battery is connected it will get charged automatically when power supply is attached with up to
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 uses Olimex’s battery polarity. If you use
batteries from other manufacturers please ma e sure PLUS and MINUS are connected properly as you WILL
damage the board!!!
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GPIO connector
Pin.1 is connected to the Li-Po 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.
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 bac ed 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 operate at +3.3V levels. This means you should not connect signals above 3.3V to 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 compatible 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 programmer.
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Jumpers
Typically you don’t need to change the positions of the jumpers to use the board.
BUZ_EN1 – buzzer enable jumper – when closed the buzzer plays the sound
commands.
Default state: Open (Buzzer disabled)
ESP_PROG1 – ESP programming enabled when closed ESP32 enters bootloader
mode at reset and can be programmed over the USB connector.
Default state: Open (ESP programming handled by software)
UART_D – UART disable – when closed the UART connection between
eZ80 and ESP32 is disconnected. This is necessary when ESP32 is
programming.
Default state: Open (communication between eZ80 and ESP32 enabled)
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