About a year ago, I bought a couple of AD9850 signal generator modules on Ebay for about $5 each. I don’t have any specific need for such a device but thought it could be interesting to see how they worked. I’ve only now got around to trying them out and I haven’t had any luck so far getting a signal out of either of them.
At this stage I’ve simply hooked up the module to an 08M2 home made module that I use for this sort of thing and I’ve used Matherp’s finished project as a guide for both hardware & software. When powered up, the red LED on the module comes on, it pulls about 100 mA and the output waveform on pin 10 rises to about 0.5 volts and sits there steadily.
I’ve included a photo of my rough setup but I don’t really expect anyone to follow it in detail. In essence, I’ve connected data lines D0 & D1 to Vcc and D2 to ground and I’ve tied the reset line to ground with a 1k resistor. I’ve connected Vcc (5 volts) & ground of both modules together. I’ve also connected the control lines between the 08M2 & the AD9850 as follows:-
C.1 - Data (leg 4 of AD9850 board)
C.2 - W_CLK (leg 2 of AD9850 board)
C.4 - FQ_UD (leg 3 of AD9850 board)
I’ve then run the program below which simply switches the module to serial mode and then reads in a 40 bit word which should set it to a frequency of 1k hertz. However I get no signal out of pin 10. I’ve looked at the signals going to the module from the 08M2 and they look fine to me.
I see in the brief documentation on the seller’s ebay site that it says “Parallel and serial data input can be selected via a jumper”. I don’t see any jumper on the board. From a read of the documentation for the AD9850, it would appear that there is no facility to select serial data via hardware so I can’t see how a jumper could function.
Has anyone else purchased this module and did you have any luck getting it going?
Any comments on what I might try next would be welcomed.
At this stage I’ve simply hooked up the module to an 08M2 home made module that I use for this sort of thing and I’ve used Matherp’s finished project as a guide for both hardware & software. When powered up, the red LED on the module comes on, it pulls about 100 mA and the output waveform on pin 10 rises to about 0.5 volts and sits there steadily.
I’ve included a photo of my rough setup but I don’t really expect anyone to follow it in detail. In essence, I’ve connected data lines D0 & D1 to Vcc and D2 to ground and I’ve tied the reset line to ground with a 1k resistor. I’ve connected Vcc (5 volts) & ground of both modules together. I’ve also connected the control lines between the 08M2 & the AD9850 as follows:-
C.1 - Data (leg 4 of AD9850 board)
C.2 - W_CLK (leg 2 of AD9850 board)
C.4 - FQ_UD (leg 3 of AD9850 board)
I’ve then run the program below which simply switches the module to serial mode and then reads in a 40 bit word which should set it to a frequency of 1k hertz. However I get no signal out of pin 10. I’ve looked at the signals going to the module from the 08M2 and they look fine to me.
Code:
#picaxe 08M2
#no_data
symbol D7=pinC.1
symbol W_CLK=C.2
symbol FQ_UD=C.4
low W_CLK
low FQ_UD
low c.1
pause 10
pulsout FQ_UD,10 'reset the address pointer to first register
pause 10
pulsout W_CLK,10 'Read in control word from 8 bit data lines
pause 10
pulsout FQ_UD,10 'Switch to serial mode input
pause 10
do
for b2=0 to 4 'Read in 5 bytes from EEPROM and send them serially to the AD9850 module
read b2,b0
for b3=1 to 8
D7=bit0
pulsout W_CLK,1
b0=b0/2
next b3
next b2
pulsout FQ_UD,10 'load 40 bit control value - update frequency
low c.1
pause 1000
loop
EEPROM 0,(56,134,0,0,0) '1k Hertz
Has anyone else purchased this module and did you have any luck getting it going?
Any comments on what I might try next would be welcomed.