|Type||CanSat Slave Gumstix||Schematic||Description|
|V1.0||CanSat Slave Gumstix v2.0 Schematic PDF|
The COM board can be powered with 5 V:
When using the micro-USB connector power supply:
- the jumper close to the the COM board should be shorted
- the jumper on the power supply board should be open on both sides (5 V from batteries or from mini-USB)
The Gumstix needs an input voltage of 3.3 – 4.2 V DC. Apart from that, little information is given by the manufacturer. Therefore we did some crude tests on our own, with the CanSat Slave Gumstix board directly connected to a laboratory power supply. The test design (developed for the Kart) serves a webpage over WiFi.
The whole setup works fine for voltages higher than 3.2V and it consumes up to 500 mA.
A breakout board with the following pins on a standard connector has been created:
|N_RESET||in||Gumstix reset, connected to GND via a pushbutton|
|SPI1 CLK||out||3.3||SPI port|
|USB5||out||5|| Power delivered by the USB connector |
not used on the breakout board
provided to the connector via a jumper
The USB5 power is connected to the top connector's 5 V pin through a jumper. This poster supply can be used for the whole CanSat system if no power is provided to the power board.
On the power board, the 3.3 V is generated for all the CanSat boards. This is the source of the VCC33 pin which powers the COM board.
The micro-USB connects to an FTDI USB to RS232 bridge. This connects to The Overo's RxD3 / TxD3 pins.
It gives access to the TTY console. Settings are: 115˙200 baud, 8 bit, no parity.
A 4-pin connector on the side of the board connects the audio signals to the Gumstix Overo.