diff --git a/_posts/2024-10-02-Dev-log-GPS-receiver-based-on-MAX2769-and-Zynq-7010-FPGA.md b/_posts/2024-10-02-Dev-log-GPS-receiver-based-on-MAX2769-and-Zynq-7010-FPGA.md
index 2074de4..70b6f0b 100644
--- a/_posts/2024-10-02-Dev-log-GPS-receiver-based-on-MAX2769-and-Zynq-7010-FPGA.md
+++ b/_posts/2024-10-02-Dev-log-GPS-receiver-based-on-MAX2769-and-Zynq-7010-FPGA.md
@@ -9,7 +9,17 @@ tags: [rf, electronics, fpga, ebaz4205, max2769, zynq7010, gps, devlog] # system
 
 ## 🚧🚧 THIS PAGE IS NOT FINISHED 🚧🚧
 
-## Notes:
+## Updates
+
+### 2024-11-15: First PCB design
+
+The openGNSS PCB is done! The tab extending down on the left side of the board is to provide a mounting point for the board to mount to the ebaz4205 board if the top mounting points cannot be used, since IREC regulations do not allow use of connectors as mechanical mounting.
+
+![Top PCB](/assets/img/2024-10-02-Dev-log-GPS-receiver/top.png)
+
+![bottom PCB](/assets/img/2024-10-02-Dev-log-GPS-receiver/bottom.png)
+
+## Notes
 
 https://github.com/iliasam/STM32F4_SDR_GPS?tab=readme-ov-file
 
diff --git a/assets/img/2024-10-02-Dev-log-GPS-receiver/bottom.png b/assets/img/2024-10-02-Dev-log-GPS-receiver/bottom.png
new file mode 100644
index 0000000..37699ef
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diff --git a/assets/img/2024-10-02-Dev-log-GPS-receiver/top.png b/assets/img/2024-10-02-Dev-log-GPS-receiver/top.png
new file mode 100644
index 0000000..e3de218
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diff --git a/assets/lib/2024-10-20-SC03C2H5OH-Electroch/checksum.c b/assets/lib/2024-10-20-SC03C2H5OH-Electroch/checksum.c
new file mode 100644
index 0000000..a873b8c
--- /dev/null
+++ b/assets/lib/2024-10-20-SC03C2H5OH-Electroch/checksum.c
@@ -0,0 +1,9 @@
+
+unsigned char get_checksum(unsigned char array[], unsigned char array_size)
+{
+    unsigned char checksum = 0;
+    for (unsigned char i = 1; i < array_size - 2; i++)
+        checksum += array[i];
+    checksum = (~checksum) + 1;
+    return checksum;
+}
\ No newline at end of file