August 9, 2016 at 12:22 am #43725
I got beer for whomever can help me with a detail list of parts needed for the latest OSPi and OSPi expansion board
thank you in advance. I did get the BOM from eagle cad but some of the components are missing info or description and since I’m not that good with electronics I haven’t figured it out yet.August 10, 2016 at 4:10 pm #43739
Well the information from the bom and the github has everything you need. I will upload the list I made but given everything is service mount parts and very small. Do some research and learn some basics how each component works else it might cost you more then just order ospi.
Attachments:August 14, 2016 at 4:53 am #43763
Thank you so much Archprlest; I actually bought the OSPi but on my board it says v1.43+ and I did not find the hardware files for it, I guess it is not open hardware anymore. There are some differences between your parts list and the board I have one of them being above the “COM” connection, the other one is the crystal on your list is a through hole component but a surface mounted one is needed Could any of you help me choose from here? I also circled a resistor with the markings “3R3”, Does anyone have a digi-key part number for it?
Also there is an IC on the parts list SN74HC595NSR but on my OSPi board it is marked as HC595AG just want to make sure that it’s ok to use the one on the list.
I made the “Part Number” on the pdf a link if anyone can please just double check it to see if those parts will work I will appreciate it.
how do I get the beer to you Archprlest?
Attachments:August 14, 2016 at 12:23 pm #43772
@adrian78666: the published files in Github is OSPi 1.42+ and the current version we sell is OSPi 1.43+. The difference is very minor (I believe the main difference is added PCB spark gaps at the back of the circuit board, and the components remain the same).
The resistor 3R3 is a 3.3 ohm power resistor. It replaces the fuse that was on OSPi 1.42+ because many users have started using RPi 3 which draws a significant amount of current that often triggers the PTC fuse. For that reason, the fuse is now replaced by a small resistor, which still provides the connection but will not trip if RPi starts to draw a lot of current. It’s hard to document all detailed changes partly because they are small changes that I am not sure if they are worth documenting. Also, I just simply forget to write them down.
Some of your other questions really just require some familiarity in electronics. For example, 32.768kHz crystals come in many different form factors, and they are mostly interchangeable. You can even solder through-hole components onto surface mount pads, and this is perfectly fine for prototypes. Markings on parts are often just part of the part number. For example, HC595 generally means it’s 74HC595 shift register. The marking may differ somehow depending on the manufacturer, but in general the marking is not the full part number because there is not enough space to put the entire part number. Many rectifier diodes are interchangeable. For example, D1 on OSPi is a standard rectifier with a minimum of 100V reverse voltage stand. So a lot of common diodes can fit there: S1B, S1D, M2, M7, 1N4002. We often use them interchangeable depending on what we have in stock.
Hope this makes sense.August 14, 2016 at 1:25 pm #43773
Thank you Ray, yes it makes sense, I apprecuate it.August 15, 2016 at 12:36 am #43781
One more question, I plan to use the raspberry pi 3 and you said that the 3R3 replaces the fuse, so can I just solder the resistor instead of the fuse on v1.42+ ?
Thank you.August 24, 2016 at 10:51 am #43865
Yes, you can. In fact, you can also just solder a wire (or a 0ohm resistor) across it. We have a large quantity of 3R3 resistor in stock, that’s why we chose it. Any small value resistor (or 0ohm) would work too.August 24, 2016 at 6:59 pm #43895
Do you by any chance have all the components for the ospi for sale like in a package?August 24, 2016 at 8:56 pm #43899
Surface mount components: no, because these are too small and takes too much time to select and pack. It’s much easier to buy them from digikey or mouser.
Through-hole components: yes, you can send a support ticket and we can arrange to send you the complete set of through-hole components. This also makes more sense as some of the through-hole components are difficult to source from digikey or mouser.
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