Alternative controller for robots
We have developed the first version of the universal board, which can serve as a simple power supply with variable voltage and current, as well as an advanced controller for all sorts of devices, starting with LED light bulbs, stepping motors, and thermal sensors to fully autonomous robots! The working title is Grambo Pi (Grambo is Gromozek's English, and Pi is from Raspberry Pi).
Grambo Pi is a programmable control board based on the ARM Cortex M3 microcontroller. It can serve for a variety of tasks related to device control and automatic sensor readings. The board can serve as a voltage source, work as a charger for batteries of various types, can control electric motors with a maximum continuous current up to 600 mA and a short-term one up to 1200 mA, it has a control circuit for the lighting LED. When designing the board, it was possible to serve as a power source for the Raspberry Pi single-board computer. The board has a set of sensors: a thermometer, an accelerometer and a compass, which allows the board to be used as an orientation system for moving devices. The board can communicate with external devices using a set of standard data exchange interfaces: USB, serial port, I2C (master and slave). The functionality of the board can be expanded by connecting expansion cards!
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The board has a built-in virtual machine that executes byte code received after compiling programs written in the Pawn language. The byte code is written to the FLASH memory and starts to be executed each time power is applied to the board. The behavior of the board and data exchange with external devices is determined by the program that is loaded into it.
There are three main ways to use the board:
In the latter case, the board can not only be controlled by the Raspberry Pi computer, but also serve as a smart power source for it. For example, the board can be configured (by a program on Pawn loaded into the internal FLASH memory) as an ATX-like power source that turns the computer on and off at the touch of a button or as a power source that is turned on according to a schedule.
The board has software-configured voltage converters. For each converter, it is possible to set the desired output voltage and limit the maximum input current. For a step-up converter, it is also possible to set the minimum input voltage. The latter allows you to use the board to generate energy from solar panels at the point with the maximum power on the IV characteristic of the battery.
The ability to connect a rechargeable battery and a solar battery allows you to get solutions that do not depend on stationary energy sources. In this case, the board and the connected devices can work in any place where there is sunlight. An energy-demanding computer may turn on from time to time when there is enough power in the battery to power it.
The board provides three ways to supply power:
In the latter case, the current received by the board is preliminarily hardware limited to 400 mA, after which it is fed to the input of a tuned step-up voltage converter.
A complete list of peripherals on the board:
All peripherals can be used from the internal Pawn program.
Using Raspberry Pi together with Grambo Pi allows you to develop solutions of almost any complexity. Starting with systems on and off according to a predetermined schedule in order to save energy consumption and ending with systems that require full computer power to perform such tasks as real-time video processing and web application support!
The functionality of the Grambo Pi can be enhanced with the help of specially designed expansion cards, which also simply fit together. You can connect multiple boards at the same time.
Expansion cards may be different. Presented in the figure has the following devices:
For ease of debugging, each board has several software-controlled indicator LEDs that can be used for visual debugging or for alerting on status.
There are several options for software interaction with the Grambo Pi:
On the side of the board, communication with the computer and control of peripheral devices is performed by the virtual Pawn machine.
Connoisseurs of robotics, would you be interested in such a module? Would you buy a copy for testing? Or would you better build your device on the Arduino platform?
Grambo Pi is a programmable control board based on the ARM Cortex M3 microcontroller. It can serve for a variety of tasks related to device control and automatic sensor readings. The board can serve as a voltage source, work as a charger for batteries of various types, can control electric motors with a maximum continuous current up to 600 mA and a short-term one up to 1200 mA, it has a control circuit for the lighting LED. When designing the board, it was possible to serve as a power source for the Raspberry Pi single-board computer. The board has a set of sensors: a thermometer, an accelerometer and a compass, which allows the board to be used as an orientation system for moving devices. The board can communicate with external devices using a set of standard data exchange interfaces: USB, serial port, I2C (master and slave). The functionality of the board can be expanded by connecting expansion cards!
')
The board has a built-in virtual machine that executes byte code received after compiling programs written in the Pawn language. The byte code is written to the FLASH memory and starts to be executed each time power is applied to the board. The behavior of the board and data exchange with external devices is determined by the program that is loaded into it.
There are three main ways to use the board:
- as an autonomous device operating independently;
- as a device controlled from a computer via a USB bus;
- in conjunction with a single-board computer Raspberry Pi.
In the latter case, the board can not only be controlled by the Raspberry Pi computer, but also serve as a smart power source for it. For example, the board can be configured (by a program on Pawn loaded into the internal FLASH memory) as an ATX-like power source that turns the computer on and off at the touch of a button or as a power source that is turned on according to a schedule.
The board has software-configured voltage converters. For each converter, it is possible to set the desired output voltage and limit the maximum input current. For a step-up converter, it is also possible to set the minimum input voltage. The latter allows you to use the board to generate energy from solar panels at the point with the maximum power on the IV characteristic of the battery.
The ability to connect a rechargeable battery and a solar battery allows you to get solutions that do not depend on stationary energy sources. In this case, the board and the connected devices can work in any place where there is sunlight. An energy-demanding computer may turn on from time to time when there is enough power in the battery to power it.
The board provides three ways to supply power:
- through the input down-converter;
- through the input of the boost converter;
- through the USB connector.
In the latter case, the current received by the board is preliminarily hardware limited to 400 mA, after which it is fed to the input of a tuned step-up voltage converter.
A complete list of peripherals on the board:
- 3-axis accelerometer;
- 3-axis compass;
- digital and analog thermometers;
- controller of 2 DC motors (or one bipolar stepper or 4 independent inductive loads) with built-in protective diodes;
- 3.3V step down converter for powering peripherals;
- adjustable down-converter with output voltage range from 0V to 16V, input current limitation from 0A to 3A;
- Adjustable boost converter with output voltage range up to 16V; input current can be limited from 0A to 3A.
- USB;
- hardware current limiter via USB up to 400mA;
- serial port UART;
- I2C master;
- I2C slave;
- power supply circuit lighting LED;
- mating connector with Raspberry Pi;
- connector for expansion cards;
All peripherals can be used from the internal Pawn program.
Using Raspberry Pi together with Grambo Pi allows you to develop solutions of almost any complexity. Starting with systems on and off according to a predetermined schedule in order to save energy consumption and ending with systems that require full computer power to perform such tasks as real-time video processing and web application support!
The functionality of the Grambo Pi can be enhanced with the help of specially designed expansion cards, which also simply fit together. You can connect multiple boards at the same time.
Expansion cards may be different. Presented in the figure has the following devices:
- 8 PWM connectors compatible with analog servo connectors;
- controller of 4 DC motors or 2 bipolar stepper motors;
- 8 ADC analog inputs with a range from 0V to 3.3V;
- 8 digital inputs (for example, for detecting button presses);
For ease of debugging, each board has several software-controlled indicator LEDs that can be used for visual debugging or for alerting on status.
There are several options for software interaction with the Grambo Pi:
- C ++ library;
- Python module for interaction through the USB port;
- Python module for interaction via I2C port (in case of connecting to Raspberry Pi);
On the side of the board, communication with the computer and control of peripheral devices is performed by the virtual Pawn machine.
Questions to the masters
Connoisseurs of robotics, would you be interested in such a module? Would you buy a copy for testing? Or would you better build your device on the Arduino platform?
Source: https://habr.com/ru/post/203124/
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