Table of Contents
Controller module ATmega2561 v1.x
The main module of the HomeLab is a controller development board (controller board) equipped with the AVR ATmega2561 microcontroller. In addition to the microcontroller, the board consists of several peripherals, voltage stabilizer, connectors, JTAG programmer, Ethernet, SD memory card slot. The controller board has the following features:
- ATmega2561-16AU microcontroller
- 8-channel 10-bit A/D converter
- 256 kB Flash memory (program memory)
- 4kB EEPROM memory (data memory)
- 6 channel programmable PWM
- Integrated JTAG programmer (based on FTDI2232)
- 14,7456 MHz clock
- Ethernet module with RJ45 connector
- SD memory card slot
- Status LED (PB7)and Power LED
- Programmable button (PC2) and reset button
- All Atmega signals available on three connectors (1: ports D, B, E; 2: ports G, C, A; 3: port F with ADC I/O lines)
- 2,1 mm power socket
- Automatic power switch USB or external power supply
- Built-in voltage stabilizer, with 5 V and 3,3 V output
Controller module
The module is equipped with a AC/DC rectifier circuit and a LDO voltage stabilizer (with low dropout) -an external feeder with voltage stabilization is not needed. The module can be powered with a step down transformer with an output voltage which is greater than 6 volts and lower than 15 volts. In order to reduce power losses it is recommended to use power supply between 6-9V. The POWER LED signalizes a connected feed (“POWER” description on the board). All ATmega2561 signals are available on three connectors on the edge of the board. Connectors pin assignment is described in the next part of this instruction. It includes full descriptions of ATmega2561 pins and their alternative functions. The module is equipped with a microprocessor reset circuit (when power on) and a reset button for a microprocessor restart. A microprocessor can be programmed with an on-board JTAG programmer over USB or with an ISP interface. To the seventh pin of port B (named as PB7) the status LED (described as PB7 on the board) is connected. This LED can be used as a status indicator of application software. Low state on PB7 pin causes the status LED to be lit. The module is equipped with SD memory card slot, where it can be used as a standard microSD memory card. The memory card is connected to the microcontroller via the ISP interface and can be used to store data where data must be maintained even if the power supply is removed.
Components on the Controller board
Connector Pins and Functions
| Nr | Pin | Alternative function / Description | |
|---|---|---|---|
| 1 | VCC | - | +5 V |
| 2 | GND | - | GND |
| 3 | REF | AREF | Analog Reference Voltage For ADC |
| 4 | GND | - | GND |
| 5 | PF0 | ADC0 | ADC Input Channel 0 |
| 6 | GND | - | GND |
| 7 | PF1 | ADC1 | ADC Input Channel 1 |
| 8 | GND | - | GND |
| 9 | PF2 | ADC2 | ADC Input Channel 2 |
| 10 | GND | - | GND |
| 11 | PF3 | ADC3 | ADC Input Channel 3 |
| 12 | GND | - | GND |
| Nr | Pin | Alternative function / Description | |
|---|---|---|---|
| 1 | PD7 | T2 | Timer/Counter2 Clock Input |
| 2 | PD6 | T1 | Timer/Counter1 Clock Input |
| 3 | PD5 | XCK1 | USART1 External Clock Input/Output |
| 4 | PD4 | IC1 | Timer/Counter1 Input Capture Trigger |
| 5 | PD3 | INT3/TXD1 | External Interrupt3 Input or UART1 Transmit Pin |
| 6 | PD2 | INT2/RXD1 | External Interrupt2 Input or UART1 Receive Pin |
| 7 | PD1 | INT1/SDA | External Interrupt1 Input or TWI Serial Data |
| 8 | PD0 | INT0/SCL | External Interrupt0 Input or TWI Serial Clock |
| 9 | VCC | - | +5V |
| 10 | GND | - | GND |
| 11 | PB7 | OC0A/OC1C/PCINT7 | Output Compare and PWM Output A for Timer/Counter0, Output Compare and PWM Output C for Timer/Counter1 or Pin Change Interrupt 7 |
| 12 | PB6 | OC1B/PCINT6 | Output Compare and PWM Output B for Timer/Counter1 or Pin Change Interrupt 6 |
| 13 | PB5 | OC1A/PCINT5 | Output Compare and PWM Output A for Timer/Counter1 or Pin Change Interrupt 5 |
| 14 | PB4 | OC2A/PCINT4 | Output Compare and PWM Output A for Timer/Counter2 or Pin Change Interrupt 4 |
| 15 | PB3 | MISO/PCINT3 | SPI Bus Master Input/Slave Output or Pin Change Interrupt 3 |
| 16 | PB2 | MOSI/PCINT2 | SPI Bus Master Output/Slave Input or Pin Change Interrupt 2 |
| 17 | PB1 | SCK/PCINT1 | SPI Bus Serial Clock or Pin Change Interrupt 1 |
| 18 | PB0 | SS/PCINT0 | SPI Slave Select input or Pin Change Interrupt 0 |
| 19 | PE7 | INT7/IC3/CLK0 | External Interrupt 7 Input, Timer/Counter3 Input Capture Trigger or Divided System Clock |
| 20 | PE6 | INT6/T3 | External Interrupt 6 Input or Timer/Counter3 Clock Input |
| 21 | PE5 | INT5/OC3C | External Interrupt 5 Input or Output Compare and PWM Output C for Timer/Counter3 |
| 22 | PE4 | INT4/OC3B | External Interrupt4 Input or Output Compare and PWM Output B for Timer/Counter3 |
| 23 | PE3 | AIN1/OC3A | Analog Comparator Negative Input or Output Compare and PWM Output A for Timer/Counter3 |
| 24 | PE2 | AIN0/XCK0 | Analog Comparator Positive Input or USART0 external clock input/output |
| 25 | PE1 | PDO/TXD0 | ISP Programming Interface Data Output or USART0 Transmit Pin |
| 26 | PE0 | PDI/RXD0/INT8 | ISP Programming Interface Data Input, USART0 Receive Pin or Pin Change Interrupt 8 |
| Nr | Pin | Alternative function / Description | |
|---|---|---|---|
| 1 | GND | - | Gnd |
| 2 | VCC | - | +5 V |
| 3 | PA0 | AD0 | External memory interface address and data bit 0 |
| 4 | PA1 | AD1 | External memory interface address and data bit 1 |
| 5 | PA2 | AD2 | External memory interface address and data bit 2 |
| 6 | PA3 | AD3 | External memory interface address and data bit 3 |
| 7 | PA4 | AD4 | External memory interface address and data bit 4 |
| 8 | PA5 | AD5 | External memory interface address and data bit 5 |
| 9 | PA6 | AD6 | External memory interface address and data bit 6 |
| 10 | PA7 | AD7 | External memory interface address and data bit 7 |
| 11 | PG4 | TOSC1 | RTC Oscillator Timer/Counter2 |
| 12 | PG5 | OC0B | Output Compare and PWM Output B for Timer/Counter0 |
| 13 | PG2 | ALE | Address Latch Enable to external memory |
| 14 | PG3 | TOSC2 | RTC Oscillator Timer/Counter2 |
| 15 | PC6 | A14 | External Memory interface address bit 14 |
| 16 | PC7 | A15 | External Memory interface address bit 15 |
| 17 | PC4 | A12 | External Memory interface address bit 12 |
| 18 | PC5 | A13 | External Memory interface address bit 13 |
| 19 | PC2 | A10 | External Memory interface address bit 10 |
| 20 | PC3 | A11 | External Memory interface address bit 11 |
| 21 | PC0 | A8 | External Memory interface address bit 8 |
| 22 | PC1 | A9 | External Memory interface address bit 9 |
| 23 | PG0 | WR | Write strobe to external memory |
| 24 | PG1 | RD | Read strobe to external memory |
| 25 | GND | - | GND |
| 26 | 3V3 | - | +3,3 V |
Connecting
When connecting the controller module with other modules or devices, you must first make sure that the controller module power supply is not connected. Modules and devices must be connected to each other with care. It is important not to use excessive force, wrong handling may damage the module. For programming and to power with low currency (less than 500mA) you must only connect the controller module with a PC using an USB port. If you are using modules that need to use a greater current than 500 mA, you must use a separate power source. If a controller module is connected to a separate power source, then the module automatically does not use USB a power supply.
Controller module connected to power supply and programmer
