build: check for some installed bins before building

deploy.sh

@@ -1,6 +1,27 @@
+check_exists() {
+    command -v "$1" > /dev/null
+}
 check_port() {
     cargo espflash board-info "$1" &> /dev/null
 }
+if ! check_exists esptool.py
+then
+    echo "esptool.py not installed!"
+    echo "install with this command: pip install esptool"
+    exit 1
+fi
+if ! check_exists ldproxy
+then
+    echo "ldproxy not installed!"
+    echo "install with this command: cargo install ldproxy"
+    exit 1
+fi
+if ! check_exists cargo-espflash
+then
+    echo "cargo-espflash not installed!"
+    echo "install with this command: cargo install cargo-espflash"
+    exit 1
+fi
 for FILE in /dev/tty.*
 do
     if check_port $FILE 
@@ -9,10 +30,10 @@ do
         break
     fi
 done
-
 if [ -z "$PORT" ]
 then
     echo "ESP likely not connected! Exiting now."
+    echo "Make sure the ESP is connected with a data USB cable, and try again."
     exit 1
 fi
 git pull