Interfacing with the AD5204
velociostrich
Posts: 40
I bought three AD5204 digital potentiometer chips from DigiKey in 24-pin SOIC form for use in a project (datasheet available from Analog's site here: http://www.analog.com/static/imported-files/Data_Sheets/AD5204_5206.pdf). At first, the datasheet made the chips seem fairly simple to interface, using SPI (something I had never tried before but found information on in the BASIC Stamp documentation). Rather than making or purchasing a breakout board, I soldered wires directly to one, then in turn to a protoboard and a header cable to a BASIC Stamp 2 SX, but I have not been able to make it work; I think I may have damaged the chip either by putting too much heat into it during soldering or by accidentally touching a lead (or leads).
Anyways, I soldered wires to another one, this time much quicker without even bridging any leads, but I have a few questions: first, what is the difference between ground and VSS -- do I just connect both to the negative power supply of the BASIC Stamp? Secondly, I was unsure of what to do with pin 10, which says that it is "an open drain transistor and requires a pull-up resistor" -- how do I know what kind of resistance to use in the pull-up resistor? Googling the subject gave me an article that explained what electrical characteristics to look for, but I did not see the ones they specified, and was unsure of what the result of the calculations they listed meant. Lastly, I can just interface with the device using SHIFTIN and SHIFTOUT, correct? It may have been simply that the code I attempted to use with the IC was in error; if anyone would like to look at it, I'd be happy to upload it.
Anyways, I soldered wires to another one, this time much quicker without even bridging any leads, but I have a few questions: first, what is the difference between ground and VSS -- do I just connect both to the negative power supply of the BASIC Stamp? Secondly, I was unsure of what to do with pin 10, which says that it is "an open drain transistor and requires a pull-up resistor" -- how do I know what kind of resistance to use in the pull-up resistor? Googling the subject gave me an article that explained what electrical characteristics to look for, but I did not see the ones they specified, and was unsure of what the result of the calculations they listed meant. Lastly, I can just interface with the device using SHIFTIN and SHIFTOUT, correct? It may have been simply that the code I attempted to use with the IC was in error; if anyone would like to look at it, I'd be happy to upload it.
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