diff --git a/README.md b/README.md
index 3f532c2..d6dac3c 100644
--- a/README.md
+++ b/README.md
@@ -27,9 +27,11 @@ feel free to push them.
Tips for adding hardware instructions:
1. Compose a chapter in a new Markdown file in `src/hw`
-2. Add pictures if needed, store them in `src/img`
+2. Add pictures if needed, store them in `src/img`, assure them to be clear, informative and compressed
+ (you can use `convert -quality 80% -resize x ` for optimizing)
3. Add link to the new chapter to the `src/SUMMARY.md`
4. Do not forget to tell about all hidden/non-obvious obstacles and pitfalls
5. Add testing steps, even if the "obvious" ones
6. Add JSON sample if needed
-7. View changed and added pages with `mdbook build` (see building instructions above)
+7. Add hardware setup (e.g. pins, switches) steps if needed
+8. View changed and added pages with `mdbook build` (see building instructions above)
diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index 2557323..c057a0d 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -4,3 +4,4 @@
- [Hardware](./hw/hardware.md)
- [Sinara 4624 AWG Phaser (Upconverter)](./hw/phaser_upconverter.md)
- [Sinara 4456 synthesizer Mirny](./hw/mirny.md)
+ - [SUServo (Sampler + Urukul)](./hw/suservo.md)
diff --git a/src/hw/suservo.md b/src/hw/suservo.md
new file mode 100644
index 0000000..0030017
--- /dev/null
+++ b/src/hw/suservo.md
@@ -0,0 +1,55 @@
+# SUServo (Sampler + Urukul)
+
+## JSON
+
+```json
+{
+ "type": "suservo",
+ "sampler_ports": [, ],
+ "urukulN_ports": [, ],
+ "urukulM_ports": [, ], // optional
+ "clk_sel": 2
+}
+```
+
+With enabled SUServo mode, you only need to add `suservo` to JSON file, with its Sampler and Urukul(s) removed.
+
+## Setup
+
+On bottoms of each Urukul, switch first pins 1 and 2 to `ON`, as on the picture:
+![](../img/urukul_pins_suservo.jpeg)
+
+## Testing
+
+```text
+*** Testing SUServos.
+Initializing modules...
+suservo0
+...done
+Setting up SUServo channels...
+suservo0_ch0
+suservo0_ch1
+suservo0_ch2
+suservo0_ch3
+suservo0_ch4
+suservo0_ch5
+suservo0_ch6
+suservo0_ch7
+...done
+Enabling...
+suservo0
+...done
+Each Sampler channel applies proportional amplitude control
+on the respective Urukul0 (ADC 0-3) and Urukul1 (ADC 4-7, if
+present) channels.
+Frequency: 10 MHz, output power: about -9 dBm at 0 V and about -15 dBm at 1.5 V
+Verify frequency and power behavior.
+```
+
+1. Connect oscilloscope to the `urukul0` port and configure with time and voltage scale and trigger threshold
+ so that you'll see sine wave, like on the picture: ![](../img/urukul_suservo_output_without_battery.jpg)
+2. Verify amplitude and frequency
+3. Apply 1.5V (connect the AA-battery) to the `sampler0` port, as on the picture: ![](../img/urukul_sampler_susevo_connections.jpg)
+4. You should see significant amplitude decrease, as in the picture: ![](../img/urukul_suservo_output_with_battery.jpg)
+5. Verify amplitude difference, and the frequency to be unchanged
+6. Repeat steps 1-5 for every available channel.
diff --git a/src/img/urukul_pins_suservo.jpeg b/src/img/urukul_pins_suservo.jpeg
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diff --git a/src/img/urukul_sampler_susevo_connections.jpg b/src/img/urukul_sampler_susevo_connections.jpg
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diff --git a/src/img/urukul_suservo_output_with_battery.jpg b/src/img/urukul_suservo_output_with_battery.jpg
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diff --git a/src/img/urukul_suservo_output_without_battery.jpg b/src/img/urukul_suservo_output_without_battery.jpg
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