Serial cable
This guide shows you how to create a serial cable.
Contents |
Serial using gadget USB
It seems it is possible to get serial connectivity using the on-board USB port. Take a look at http://www.gp32x.com/board/index.php?showtopic=24053 for more info.
How to create a serial cable
There are multiple ways of creating a serial cable. Chose one according to your knowledge, time constraints, etc..
- Create a cable by soldering a simple circuit involving a MAX3223 level shifter. This will connect your 12V serial connector (RS-232) to the 3V serial connector of the GP2X.
- Resolder an original Samsung E810 data cable which already contains a level shifter chip and follows the wiring instructions given here: SamsungE810Cable
- Rewire a cheap non-original E810 USB data cable. This may involve no soldering, a multimeter is however strongly recommended. This lets you attach your GP2x serial console to an USB port which is more common and convenient than RS-232 these days. Follow these instructions: SamsungE810USBCable
Building the circuit
Schematic
The EXT connector
The serial cable uses the serial I/O functionality found on the EXT Port. You will need to get one of the available EXT Port connectors.
Components
Part list
- 1x MAX3232
- 5x capacitator 100nF (C1-C5)
- 1x SUB-D connector (9 pins, female)
- 1x EXT connector
Part numbers for ordering
| Part Numbers | ||||
|---|---|---|---|---|
|
Quantity |
Description |
|||
| 1 | MAX 3232 CPE 3,0 to 5,5V low power up to 1mbps true rs-232 | MAX 3232 CPE | DT26D | MAX3232ECPE-ND |
| 5 | Capacitator 100nF | TANTAL 0,1/35 | WW54J | 493-2336-1-ND |
| 1 | SUB-D connector (9 pins, female) | D-SUB BU 09 | RK61R | |
| 1 (optional) | experimental board (for building the circuit) | UP 932HP | JP52G | |
| 1 (optional) | IC socket (16 pins - for MAX3232) | GS 16 | BL19V | |
Connection
Powering up will echo both u-boot and the bootup process to the serial port of the gp2x. If you are not seeing anything on your PC, try another serial port or check the wiring of your serial cable.
Windows
Start HyperTerminal and create a new connection with the following settings:
- 115200 bps
- 8 bits
- No parity
- 1 stop bit
- Hardware flow control: Xon/Xoff
Linux
- run minicom
- configure the comm parameters (CTRL-A, Z, P): 115200 8N1
- hit enter to return to the serial terminal and boot the gp2x to watch what happens
Misc info
Here are some pages with details on the TTL->RS232 conversion required:
