Merge pull request #907 from fabaff/patch-6

Add board details

_board/particle_argon.md

@@ -17,11 +17,38 @@ features:
   - Breadboard-Friendly
 ---
 
-This board hasn't been fully documented yet. Please make a pull request adding more info to this file.
+The Argon is a powerful Wi-Fi enabled development kit that can act as a standalone Wi-Fi endpoint. It is based on the Nordic nRF52840 and has built-in battery charging circuitry so it’s easy to connect a Li-Po and deploy your local network in minutes. 
 
-The description should be written to inform a CircuitPython user what makes the board unique and link to relevant info about it.
+The Argon is great for connecting projects or as a gateway to connect an entire group of local endpoints. It's everything you love about the Photon, with more features like Bluetooth.
+
+## Technical details
+
+* Espressif ESP32-D0WD 2.4 GHz Wi-Fi coprocessor
+  - On-board 4 MB flash for ESP32
+  - 802.11 b/g/n support
+  - 802.11 n (2.4 GHz), up to 150 Mbps
+* Nordic Semiconductor nRF52840 SoC
+  - ARM Cortex-M4F 32-bit processor @ 64MHz
+  - 1 MB flash, 256 KB RAM
+  - IEEE 802.15.4-2006: 250 Kbps
+  - Bluetooth 5: 2 Mbps, 1 Mbps, 500 Kbps, 125 Kbps
+  - Supports DSP instructions, HW accelerated Floating Point Unit (FPU) calculations
+  - ARM TrustZone CryptoCell-310 Cryptographic and security module
+  - Up to +8 dBm TX power (down to -20 dBm in 4 dB steps)
+  - NFC-A tag
+* On-board additional 4 MB SPI flash
+* 20 mixed signal GPIO (6x Analog, 8x PWM), UART, I2C, SPI
+* Micro USB 2.0 full speed (12 Mbps)
+* Integrated Li-Po charging and battery connector
+* JTAG (SWD) Connector
+* RGB status LED
+* Reset and Mode buttons
+* On-board 2.4 GHz PCB antenna for Thread/BLE (does not support Wi-Fi)
+* Two U.FL connectors for external antennas (one for Thread/BLE, another for Wi-Fi)
+* Meets the Feather specification in dimensions and pinout
 
 ## Purchase
+
 * [Argon Kit - Particle](https://store.particle.io/products/argon-kit)
 * [Board Only - Adafruit](https://www.adafruit.com/product/3997)
 * [Argon Kit - Adafruit](https://www.adafruit.com/product/3993)