search

SasaKaranovic / winfidel-sensor

Wireless Inline Filament Diameter Estimator Low-cost Sensor
https://sasakaranovic.com
174 stars 11 forks source link

C7, C8 are DNP and not in the BOM. What does DNP mean? #5

Open johndeere6110 opened 4 months ago

johndeere6110 commented 4 months ago

unnamed

hello

When I want to buy the PCB, I am asked what should be placed in these places and I cannot find what should be placed there, can you help me?

SasaKaranovic commented 4 months ago

Please take a look at the schematic and/or BOM. Components that you marked are A1, C7, R11, C8 from left to right respectively.

johndeere6110 commented 4 months ago

I understand, but I can find it in the schematic, C7-C8 but it is not in the BOM so I don't know which capacitor should be there. Bill of Materials-ESP_Infidel.xlsx IMG-20240618-WA0002

SasaKaranovic commented 4 months ago

@johndeere6110 those parts are marked as DNP or Do Not Populate. Also sometimes interpreted as do not purchase/place etc) and they will not appear in the BOM. So you would not solder these components on the board.

You might ask "Why then put them in the design if you know you are not going to populate them?" There are many valid reasons to do so. In this particular case these are placeholders to be used used for antenna tuning.