diff --git a/todo.org b/todo.org
index 9ef29c8..8143efe 100644
--- a/todo.org
+++ b/todo.org
@@ -73,7 +73,7 @@ The other way around, when the owner of the device is riding the bike,
 then there's no need to send GPS, or Accelerometer data to the server.
 
 Also, the battery status could be measured at different intervals that
-GPS and acceleration, depending on the mode the device is in ofc.
+GPS and acceleration, depending on the mode the device is in.
 
 Therefore we send every measurment separately for every device.
 
@@ -151,7 +151,7 @@ server.
 Then in some function executed in a thread ...
 
 #+begin_src rust
-  fn write_gprs(modem: GsmModem, rx: Receiver) -> Result<()> {
+  fn write_gprs(modem: GsmModem, rx: Receiver<SensorData>) -> Result<()> {
       let json_for_server = match rx.recv() {
 	  GPS(coordinates) => serde_json::to_string(&coordinates)?,
 	  Battery(status) => serde_json::to_string(&status)?,
@@ -164,12 +164,12 @@ Then in some function executed in a thread ...
 * Device and phone registration
 #+begin_src plantuml :file img/registration.png
 Phone -> Device: Get device ID
-Device --> Phone: Device ID
+Phone <-- Device: Device ID
 
 Phone -> Server: Register IDs (device_id, phone_id)
 Phone <-- Server: Client TLS certificate
 Phone -> Device: Set TLS certificate
-Phone <-- Device: TLS certificate set
+Phone <-- Device: OK
 
 Device -> Server: ID verification request
 Device <-- Server: ID verification response