To preface this, I have the AD9102 chip itself, not an evaluation board package.
When I measure at the output, I'm not seeing any discernible signal.
I tried using several different references from questions asked here (AD9106 Minimum Hardware Set and https://ez.analog.com/thread/35554#120890)), but I'm not seeing any changes in my output.
I have set up my system with PIC18F4455 as the SPI master. I am electing to use software SPI for unrelated reasons, and have verified that my SPI clock is being sent from the uC, as well as the data lines in and out.
At the connections of the DDS:
- uC to DDS connections
- My SDO on the uC is being fed to the SDIO pin
- My SDI on the uC is being fed to the SDO pin
- SCK to SCK
- Trigger sent to Trigger
- Reset sent to Reset
- CS sent to CS
- Clock connections (20 MHz clock)
- Single-ended clock output to CLKP
- CLKN is connected to ground via 0.1uF cap
- CLKVDD connected to my voltage
- CLKGND grounded
- Other connections
- IOUTP is connected to ground via 500 ohm resistor
- IOUTN is connected to ground via 500 ohm resistor
The program that I'm using follows this order:
output_high(CS); output_high(Trigger); output_high(Reset); // SPICONFIG addr[0] = 0x0000; val[0] = 0x0000; // POWERCONFIG addr[1] = 0x0001; val[1] = 0x0000; // CLOCKCONFIG addr[2] = 0x0002; val[2] = 0x0000; // DDS_TW32 addr[3] = 0x003E; val[3] = 0xFFFF; // DDS_TW1 addr[4] = 0x003F; val[4] = 0xFF00; // DACAGAIN //addr[5] = 0x0007; //val[5] = 0x0400; // DAC_DGAIN addr[5] = 0x0035; val[5] = 0x0400; // DACDOF addr[6] = 0x0025; val[6] = 0x0000; // DAC_CST addr[7] = 0x0031; val[7] = 0xFF00; // DACRSET addr[8] = 0x000C; val[8] = 0x801A; // WAV_CONFIG addr[9] = 0x0027; val[9] = 0x0001; //0x0031; // PAT_TYPE addr[10] = 0x001F; val[10] = 0x0000; // RAMUPDATE addr[11] = 0x001D; val[11] = 0x0001; // PAT_STATUS addr[12] = 0x001E; val[12] = 0x0001; // RAMUPDATE addr[13] = 0x001D; val[13] = 0x0001;
The handling goes something like this:
for(i=0; i< 14; i++)
{
output_low(CS);
spi_xfer(addr[i]);
spi_xfer(val[i]);
output_high(CS);
}
output_low(Trigger);
Am I missing a register operation somewhere? Or is it more likely that I have a mis-configured connection somewhere?
