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+Mode 4 provides a SUMP/OLS-compatible logic analyzer interface, usable with sigrok/PulseView etc.
+
+## Pinout
+
+### Raspberry Pico
+
+On the Raspberry Pico, 16 channels are available:
+
+| Pin number | Usage          | Usage          | Pin number |
+|:---------- |:-------------- | --------------:| ----------:|
+| GP0        | stdio UART TX  |                | VBUS       |
+| GP1        | stdio UART RX  |                | VSYS       |
+| GND        | <ground> | <ground> | GND        |
+| GP2        |                |                | 3V3 EN     |
+| GP3        |                |                | 3V3 OUT    |
+| GP4        |                |                | ADC VREF   |
+| GP5        |                |                | GP28 / ADC2|
+| GND        | <ground> | <ground> | GND  / AGND|
+| GP6        | Channel 0      |                | GP27 / ADC1|
+| GP7        | Channel 1      |                | GP26 / ADC0|
+| GP8        | Channel 2      |                | RUN        |
+| GP9        | Channel 3      | Test PWM signal| GP22       |
+| GND        | <ground> | <ground> | GND        |
+| GP10       | Channel 4      | Channel 15     | GP21       |
+| GP11       | Channel 5      | Channel 14     | GP20       |
+| GP12       | Channel 6      | Channel 13     | GP19       |
+| GP13       | Channel 7      | Channel 12     | GP18       |
+| GND        | <ground> | <ground> | GND        |
+| GP14       | Channel 8      | Channel 11     | GP17       |
+| GP15       | Channel 9      | Channel 10     | GP16       |
+| <end>| <bottom> | <bottom> | <end>|
+
+The implementation has been lifted from [picoprobe-sump](https://github.com/perexg/picoprobe-sump), for which we thank the author a lot.
+
+## Usage
+
+### sigrok-cli
+
+```
+sigrok-cli --driver=ols:conn=/dev/ttyACM0 --config samplerate=50Mhz --samples 256 --channels 0-1
+```
+
+### PulseView
+
+Select the "Openbench Logic Sniffer" as probe type, select serial connection, where the device should show up. Any baudrate should work.
+
+Alternatively,
+
+```
+pulseview --driver=ols:conn=/dev/ttyACM0
+```
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