Build a programming cable ?

[jeanbatfr]

Hello, I bought 2 of this locators but it didn't came with the programing cable. Do you think I can build one ? Do I need a rs232 to usb converter or something ? Thank you

[speters]

Yes, you need to establish a serial connection. The factory-supplied adapter is a PL2301A based USB-to-serial adapter. I uploaded pictures of this USB-to-serial adapter PCB: bottom side with PL2301A and possibly some level-adjusting circuitry top side with an XTAL

• GND is connected to the outer sleeve of the (larger) DC barrel connector.
• Label "RX" on adapter is connected to the outer sleeve of the smaller barrel connector. It is routed on the main PCB via a 120ohms resistor to USART1_RX of the STM32.
• Label "TX" on adapter is connected to the inner contact the smaller barrel connector. It is routed on the main PCB via a 120ohms resistor to USART1_TX of the STM32.

Considering this, I suppose a simple USB-serial adapter with 3.3V levels should do fine, and wiring TX of the buoy to RX of the USB adapter, RX of buoy to TX of the USB adapter, and connecting ground should be enough to make it work.