oscilloscope/bus sniffer
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so i've decided to shy away from the adc12040's right now and am working with the adc08100's now. smaller pin count, less resolution, simpler construction. after about 100 tries i finally got the pcb made using the toner transfer method. turns out you can use regular paper for that. would've been nice to know the first 50 tries, anyways.... im wiring up the board at the moment. so perhaps tomorrow i will have some basic functionality. just reading an analog value without any scaling or triggers or anything fancy.
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the adc08100's are not treating me well :/ can't seem to get any sensible data out of them. my birthday is coming up soon so i should be able to get a laminator to help me make some pcb's. i have a box full of different types of adc's, so ill play around with them this week and see if i cant get something working here.
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so i just found a nice laser printer at goodwill for $10. soon i will have a laminator, and with those two i will try again to make some decent pcb's.
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It's really nice to see you keeping updates on the project.
Good luck making the PCB's!
Good luck making the PCB's!
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what a coincidence. my aunt's office had a broken laminator they were throwing away. doesn't laminate but looks like it's perfect for pcb making. this thing has a beast of a motor inside. hopefully tonight my pcb's will start coming out correctly.
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so invested some birthday money into my pcb lab. i now have a little etchant tank with a pump to circulate the ferric chloride, a laminator to heat and transfer the toner from old magazine paper to my copper, and a laser printer to print my designs with. i also bought some rosin flux. i read the label on my old flux and found it had zinc in it... no wonder i had short circuits. even still, i cannot get my adc08100's to work! it is very frustrating. the tlc5510ains that i tried worked beautifully though, but they are limited to 20MSPS. i will go ahead and continue development with them for now, just to get the front end working. it will be a while before the software gets to any polished state. i am questioning my use of ks0108 displays. i love them to death, but their resolution is really looking to be a problem. also, i just found employment as a mechanic, so my free time will become more limited. i will try to update more often and publish some schematics once i draw them up.
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Really looking forward to seeing how those pcb's turn out!
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so the bad news is that my xc-1a board is now fried. i think i dropped a bit of ferric chloride onto my board and shorted out the power supply. no more 3.3v and no connection to the computer. hopefully ill be able to save up for a new one. i just finished the pcb for a pga117 programmable gain amplifier. also got a bunch of other parts in, some isolated dc/dc converters for the front end, more tlc5510ains adc's, and some miscellaneous parts. i should have a working front end in about 5 more days. i'll be using my arduino for development until i can afford a replacement xmos unit :( ill finish this one way or another.
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so i made a breakout board for a texas instruments pga117 programmable gain amplifier. super simple to use, no external components, bam. i now have an analog mux and some gain. so my thinking right now is ill have some op-amp input stages. stage 1 is a variable adder, where i feed the output of a DAC to an op-amp adder so that negative voltages will be within my 0 to 3.3v adc range. after that i will have a subtractor to move the voltage range down for reading higher voltage, then that will feed through the pga117, which will feed the tlc5510ains ADC. i cannot get any of my high speed ADC's working right now so my temporary bandaid is to use a bunch of ADC's working in parallel. if i have 10 adc's at the same time, they only have to read at 1/10th the speed :D a horrible idea for sure but i have a lot of time and pretty much no more money. ill be saving up for a new xc-1a board, hopefully i can get one by the end of next month. i will try super hard to get some pictures and schematics!!!! sorry for the wait. my phone's camera is dead. will update soon
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if anyone wants the circuit board designs just send me a message. i have a breakout board for a tlc5510ains and a pga117. they are just png images, printed at 300dpi. they are designed to be printed and transferred to a pcb using the toner transfer method.