From 100b8e06332d935cd8c1422663be0c4ca1152968 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Moritz=20M=C3=BCnch?= <moritzmuench@mailbox.org>
Date: Mon, 9 Dec 2019 23:26:37 +0000
Subject: [PATCH] update

---
 README.md  |  6 +++++-
 stepper.py | 12 ++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 990cdaf..2834963 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,8 @@
 
 stepper motor control via RPi
 
-## A4988 driver wiring
+# A4988 driver
+## wiring
 GND     3-5.5V ground                   DIRECTION   -> pi gpio
 VDD     3-5.5V logic power supply       STEP
 1B      stepper coil 1                  SLEEP       --l
@@ -11,3 +12,6 @@ VDD     3-5.5V logic power supply       STEP
 2B      stepper coil 2                  MS2         -> pi gpio
 GND     8-35V ground                    MS1         -> pi gpio
 VMOT    8-35V stepper power supply      ENABLE      -> pi gpio
+
+## current limiting
+Find the two sense Resistors `Rs1` and `Rs2`. They are usually on the same side of the pcb like the chip and have Values like 0.05 Ohm, 0.068 Ohm and 0.1 Ohm. Now measure the Reference Voltage without VMOT power supply but only power supply between the potientiometer and GND 3-5.5V. It should be `VREF = IMAX * 8 * Rs. And set it accordingly.
diff --git a/stepper.py b/stepper.py
index ded0c43..fcdcb18 100644
--- a/stepper.py
+++ b/stepper.py
@@ -85,12 +85,12 @@ if __name__ == '__main__':
 
     try:
         s = Stepper([22, 27, 17])
-        s.enable()
-        s.step(100, 'left')
-        sleep(1)
-        s.step(100)
-        sleep(1)
-        s.rotate(360)
+#         s.enable()
+#         s.step(100, 'left')
+#         sleep(1)
+#         s.step(100)
+#         sleep(1)
+        s.rotate(360000)
         sleep(1)
         s.rotate(360, 'ccw')
         sleep(1)