| Electronics > Beginners |
| how to get a waveform to show up on a screen? |
| (1/1) |
| Dmeads:
Hey! I am trying to build a heart rate monitor, and I want to be able to see the output waveform on a little lcd or OLED screen. Does anyone know how to do this? Is there like a mini oscilloscope that does this? the signal isn't that large like 7 volts probably, so I wouldnt need a giant screen. Also are the screens high input impedence? |
| radiolistener:
7 V is a bit large for direct ADC input. So, you're need simple voltage divider before ADC input. Also it needs to add analog bandbass filter, to eliminate high frequency noises and pulses. Then you're need to capture ADC output at fixed sample rate and record it into memory. Then render it into video memory of LCD controller. I think you will need memory for at least 10-30 seconds. Most likely 3-10 kHz sample rate will be enough for you to capture all details. With 10 kHz and 30 sec, you will need memory buffer for about 300 kilosamples. Here is some application note, which may be useful to get started: https://www.nxp.com/docs/en/application-note/AN4059.pdf?&%3Btid=AMdlDR |
| Dmeads:
thanks!!! |
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