Why are you separating this into two transactions? It is very uncommon.
On Feb 10, 2016 5:09 AM, "Lumi" <[email protected]> wrote:
> Hello
>
> I found a figure (attached) explaining how the communication should take
> place, I believe this helps to clarify the issue.
>
> Thanks.
>
> On Wednesday, February 10, 2016 at 12:33:25 PM UTC+1, Lumi wrote:
>>
>> Dear all,
>>
>> I am trying to talk with an external device via ioio-otg twi ports. I
>> would like to write and read data to/from the registers of my external
>> device.
>>
>> Here are samples from my code:
>>
>> byte[] request=new byte[]{0x01}; //data that I want to write
>> byte[] response = new byte[13];
>>
>>
>> In setup()( function:
>>
>>
>> i2c=ioio_.openTwiMaster(2, TwiMaster.Rate.RATE_100KHz, false);
>>
>>
>> In loop() function:
>>
>>
>> if(i2c.writeRead(0x63, false, request, request.length, null, 0)) { //Here, I
>> only want to write
>>
>> if (i2c.writeRead(0x63, false, null, 0, response, response.length))// Here,
>> I only want to read
>> {
>> for (int i = 0; i < 13; i++) {
>> pw.print(String.format("%02X", response[i]));
>> pw.print(" ");
>> }
>>
>> }
>>
>>
>> Both writeRead() functions return true.
>>
>> However, the data 0x01 in request array is interpreted as an internal
>> address of a register in the device. I could not get 0x01 interpreted as
>> data and written into external device register.
>>
>>
>> This may not be very clear, but maybe there are some people who can already
>> spot the problem.
>>
>>
>> Thank you in advance,
>>
>> Regards.
>>
>>
>>
> On Wednesday, February 10, 2016 at 12:33:25 PM UTC+1, Lumi wrote:
>>
>> Dear all,
>>
>> I am trying to talk with an external device via ioio-otg twi ports. I
>> would like to write and read data to/from the registers of my external
>> device.
>>
>> Here are samples from my code:
>>
>> byte[] request=new byte[]{0x01}; //data that I want to write
>> byte[] response = new byte[13];
>>
>>
>> In setup()( function:
>>
>>
>> i2c=ioio_.openTwiMaster(2, TwiMaster.Rate.RATE_100KHz, false);
>>
>>
>> In loop() function:
>>
>>
>> if(i2c.writeRead(0x63, false, request, request.length, null, 0)) { //Here, I
>> only want to write
>>
>> if (i2c.writeRead(0x63, false, null, 0, response, response.length))// Here,
>> I only want to read
>> {
>> for (int i = 0; i < 13; i++) {
>> pw.print(String.format("%02X", response[i]));
>> pw.print(" ");
>> }
>>
>> }
>>
>>
>> Both writeRead() functions return true.
>>
>> However, the data 0x01 in request array is interpreted as an internal
>> address of a register in the device. I could not get 0x01 interpreted as
>> data and written into external device register.
>>
>>
>> This may not be very clear, but maybe there are some people who can already
>> spot the problem.
>>
>>
>> Thank you in advance,
>>
>> Regards.
>>
>>
>> --
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