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NRF_Bootloader.md

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+Using Nordic Bootloader
+========================
+
+Building complete hex file for Nordic DK upload
+------------------------------------------------
+
+Build the Bootloader:
+
+```
+make clean;PUCKJS=1 RELEASE=1 BOOTLOADER=1 make
+```
+
+Now build everything:
+
+```
+make clean;PUCKJS=1 RELEASE=1 make
+```
+
+Connect SWD connections and use:
+
+```
+PUCKJS=1 RELEASE=1 make flash
+```
+
+(Or just copy the zip file to the NRF52DK's flash drive)
+
+Building zip file for Over the Air upload
+-----------------------------------------
+
+### Prep
+
+https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v12.0.0%2Flib_crypto.html&anchor=lib_crypto_key
+
+```
+sudo apt install python-pip
+pip install --upgrade pip
+sudo pip install setuptools
+sudo pip install nrfutil
+```
+
+### Compilation
+
+```
+make clean;PUCKJS=1 RELEASE=1 DFU_UPDATE_BUILD=1 make
+```
+
+# Flashing
+
+* Download the `nRF Toolbox` app to your phone
+* Download the ZIP file to a local folder on your phone
+* Run the app and tap 'DFU'
+* Select the file (Distribution Packet)
+* Now take the battery out of the puck and re-insert it with the button hold down
+* The Green LED should be lit - now release the button (under 3 secs after inserting battery)
+* The Red LED should now be lit
+* Tap 'select device' in the app, and choose `DfuTarg`
+* Now tap `Upload`
+
+Upload Failed: UNKNOWN (8202)