Really embarrassed about using the wrong pins, but switching to 5v tolerant pins now did not solve the issue (new IOIO board just to make sure). I have a 10k pull up on both the input and output. Think it will be easier to just use another GSM module at this stage.
On Wednesday, 28 October 2015 01:42:05 UTC+2, Ytai wrote: > > Pins 39, 40 are not 5V tolerant. You really shouldn't connect a 5V signal > to them. They may already be damaged at this point. > See this wiki page for information on how to interface the IOIO with 5V > logic: > https://github.com/ytai/ioio/wiki/Digital-IO > Make sure to use 5V tolerant pins for both. You definitely need a pull-up > to 5V on the output and might as well have one on the input. > I totally don't get the design of the RX/TX circuit on the EFCOM > schematic. Either it's totally weird or I'm missing some very clever trick. > Definitely not a standard way of shifting voltage levels... > > On Tue, Oct 27, 2015 at 3:06 AM, Andries Kruger <[email protected] > <javascript:>> wrote: > >> Hi, >> >> I'm trying to integrate a GSM modem to my project (EFCOM PRO from Elec >> Freaks). I can connect the module to my pc fine using a usb to uart >> converter, send AT commands and receive the responses. >> >> When trying to connect it to the IOIO, I cannot receive the reply. I am >> using pins 39 and 40 (tx and rx). Now I know that the modem replies >> correctly as I have sent a command from the IOIO and received it using the >> USB-UART converter and TeraTerm. >> >> I use the following code to set up my UART: >> >> //Setup Comms UART >> DigitalInput.Spec rx = new DigitalInput.Spec(40, >> DigitalInput.Spec.Mode.PULL_UP); >> DigitalOutput.Spec tx = new >> DigitalOutput.Spec(39,DigitalOutput.Spec.Mode.OPEN_DRAIN); >> commsUart = ioio_.openUart(rx, tx, 9600, Uart.Parity.NONE, >> Uart.StopBits.ONE); >> commsRx = commsUart.getInputStream(); >> commsTx = commsUart.getOutputStream(); >> >> >> Am I doing anything wrong here? Any advice or tips would be greatly >> appreciated. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "ioio-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at http://groups.google.com/group/ioio-users. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "ioio-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/ioio-users. For more options, visit https://groups.google.com/d/optout.
