Center images and adjust size (can be further readjusted).

Author: aentinger

libraries/OPAMP/README.md

@@ -40,7 +40,9 @@ Both the Uno R4 Minima and WiFi feature their OPAMP channel 0 output on the same
 * Analog A2: Minus
 * Analog A3: Output
 
-![symbol](amp_symbol.png)
+<p align="center">
+  <img src="amp_symbol.png"></a>
+</p>
 
 (Vs+ is fixed to about 5V, Vs- is fixed to GND.)
 ## Testing
@@ -53,6 +55,10 @@ For an amplifier circuit, see https://www.electronics-tutorials.ws/opamp/opamp_3
 
 Below is a capture of an oscilloscope in which a circa 2V square-wave (green, channel 2) is amplified to 4V square-wave (yellow, channel 1) with the aforementioned circuit. The input signal was generated by a function generator (and shared GND was connected).
 
-![amp](amp_screenshot.png)
+<p align="center">
+  <img src="amp_screenshot.png" width="75%"></a>
+</p>
 
-![amp_circuit](amp_circuit.png)
+<p align="center">
+  <img src="amp_circuit.png" width="40%"></a>
+</p>