From 6017e6a00ca9aaed2f0391ed5d863638a37c28bf Mon Sep 17 00:00:00 2001
From: Erik Johansson <erik@ejohansson.se>
Date: Mon, 19 Nov 2018 21:03:04 +0100
Subject: [PATCH] Add Beurer protocol specification

---
 doc/protocols/beurer.md | 170 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100644 doc/protocols/beurer.md

diff --git a/doc/protocols/beurer.md b/doc/protocols/beurer.md
new file mode 100644
index 00000000..e77c6596
--- /dev/null
+++ b/doc/protocols/beurer.md
@@ -0,0 +1,170 @@
+Beurer
+======
+
+General
+-------
+
+* `<sb>`: start byte (e7 or f7)
+* `<alt sb Y>`: alternative start byte (eY or fY)
+* `<uid>`: user ID (8 bytes, BE)
+* `<name>`: 3 characters (bytes)
+* `<timestamp>`: unix timestamp (4 bytes)
+* `<weight>`: 2 bytes, BE (unit g / 50)
+* `<impedance>`: 2 bytes, BE
+
+All protocol bytes are in hex. Writes are done to characteristic
+0xffe1 on the service 0xffe0. This is also where notifications are
+received from.
+
+
+Initialization
+--------------
+
+1. Enable notifications.
+2. Write: `<alt sb 6> 01`
+3. Notification: `<alt sb 6> 00 20`
+4. Write: `<alt sb 9> <timestamp>`
+5. Write: `<sb> 4f <8 bytes 00>`
+6. Notification: `<sb> f0 4f <??> <battery> <wthr> <fthr> <unit> <ue> <urwe> <ume> <version>`
+
+* `<battery>`: battery level
+* `<wthr>`: weight threshold (unit g / 100)
+* `<fthr>`: fat threshold
+* `<unit>`: 1 = kg, 2 = lb, 3 = st
+* `<ue>, <urwe>, <ume>`: user (reference weight, measurement) exists
+* `<version>`: scale version
+
+
+### Configure threshold
+
+1. Write: `<sb> 4e <wthr> <fthr>`
+2. Notification: `<sb> f0 4e 00`
+
+
+### Set unit
+
+1. Write: `<sb> 4d <unit>`
+2. Notification: `<sb> f0 4d 00`
+
+
+### Force disconnect
+
+1. Write: `<alt sb a> 2`
+
+
+Users
+-----
+
+### Request user list
+
+1. Write: `<sb> 33`
+2. Notification: `<sb> f0 33 00 <count> <max>`
+3. Notification: `<sb> 34 <count> <current> <uid> <name> <year>`
+4. Write: `<sb> f1 34 <count> <current>`
+5. Goto 3 if `<count> != <current>`
+
+
+### Get user info
+
+1. Write: `<sb> 36 <uid>`
+2. Notification: `<sb> f0 36 00 <name> <year> <month> <day> <height> <sex|activity>`
+
+* `<month>`: January == 0
+* `<sex|activity>`: sex (female = 0x00, male = 0x80) | activity level 1 - 5
+
+
+### Add new user
+
+1. Write: `<sb> 31 <uid> <name> <year> <month> <day> <height> <sex|activity>`
+2. Notification: `<sb> f0 31 00`
+3. Perform initial measurement.
+
+Status in notification: 00 (ok), 01 (full), 02 (uid taken), 03 (name used)
+
+### Update user
+
+1. Write: `<sb> 35 <uid> ... (same as when adding user)`
+2. Notification: `<sb> f0 35 00`
+
+
+### Delete user
+
+1. Write: `<sb> 32 <uid>`
+2. Notification: `<sb> f0 32 00`
+
+
+Measurements
+------------
+
+### Perform measurement
+
+1. Write: `<sb> 40 <uid>`
+2. Notification: `<sb> f0 40 00`
+3. Notification: `<sb> 58 <status> <weight>`
+4. Write: `<sb> f1 58 <status> <weight MSB>`
+5. Goto 3 if `<status> != 0`
+6. Notification: `<sb> 59 <count> <current> 01 <uid>`
+7. Write: `<sb> f1 59 <count> <current>`
+8. Notification: `<sb> 59 <count> <current> <11 bytes data>`
+9. Write: `<sb> f1 59 <count> <current>`
+10. Goto 8 if `<count> != <current>`
+
+* Step 1 selects the user with the given ID.
+* `<status>`: 0 for stable measurement, 1 otherwise
+* All `<data>` from step 8 is joined and parsed as a measurement.
+
+
+### Request saved measurements
+
+1. Write: `<sb> 41 <uid>`
+2. Notification: `<sb> f0 41 <count> 00`
+3. Notification: `<sb> 42 <count> <current> <11 bytes data>`
+4. Write: `<sb> f1 42 <count> <current>`
+5. Goto 3 if `<count> != <current>`
+
+* All `<data>` from step 3 is joined and parsed as a measurement.
+
+
+### Delete saved measurements
+
+1. Write: `<sb> 43 <uid>`
+2. Notification: `<sb> f0 43 00`
+
+
+### Measurement
+
+22 bytes of data:
+
+`<timestamp> <weight> <impedance> <fat> <water> <muscle> <bone>
+<BMR> <AMR> <BMI>`
+
+
+Unknown measurements
+--------------------
+
+### Request unknown measurements
+
+1. Write: `<sb> 46`
+2. Notification: `<sb> f0 46 00`
+3. Notification: `<sb> 47 <count> <current> <mem> <timestamp> <weight> <impedance>`
+4. Write: `<sb> f1 47 <count> <current>`
+5. Goto 3 if `<count> != <current>`
+
+* `<mem>`: index in memory (stays constant after removal)
+
+
+### Assign unknown measurement
+
+1. Write: `<sb> 4b <uid> <timestamp> <weight> <impedance> <mem>`
+2. Notification: `<sb> f0 4b 00`
+3. Notification: `<sb> 4c <count> <current> <11 bytes data>`
+4. Write: `<sb> f1 4c <count> <current>`
+5. Goto 3 if `<count> != <current>`
+
+* All `<data>` from step 3 is joined and parsed as a measurement.
+
+
+### Delete unknown measurement
+
+1. Write: `<sb> 49 <mem>`
+2. Notification: `<sb> f0 49 00`