diff options
| author | Sadeep Madurange <sadeep@asciimx.com> | 2025-12-07 18:37:18 +0800 |
|---|---|---|
| committer | Sadeep Madurange <sadeep@asciimx.com> | 2025-12-07 18:37:18 +0800 |
| commit | d952c91adb52d0bf7dd9aff9966b930325141f75 (patch) | |
| tree | 4520b278115973ef4d94dbda994f145ae23013f3 /_projects | |
| parent | 52a2f45e8d6566e398adb7e3a7d0adde71401c3e (diff) | |
| download | www-d952c91adb52d0bf7dd9aff9966b930325141f75.tar.gz | |
Polish the PCB design write-up.
Diffstat (limited to '_projects')
| -rw-r--r-- | _projects/my-first-pcb.md | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/_projects/my-first-pcb.md b/_projects/my-first-pcb.md index be425f4..7674353 100644 --- a/_projects/my-first-pcb.md +++ b/_projects/my-first-pcb.md @@ -39,22 +39,22 @@ the door over an encrypted RF channel. </tr> </table> -The PCBs have two layers. A copper region serves as the ground plane. The 0.3 -mm wide 1 oz/ft<sup>2</sup> copper traces can carry up to 500 mA (the tracks -connecting the power source and the linear regulators have a width of 0.5 mm). +The PCBs have two layers. A copper region serves as the ground plane. The 0.3mm +wide 1oz/ft<sup>2</sup> copper traces can carry up to 500mA (the tracks +connecting the power source and the linear regulators have a width of 0.5mm). Both subsystems were functional. I was able to control the servo reliably using the fingerprint sensor. The designs aren't without flaws, however. The main shortcoming of the circuits is that they draw significant amounts of quiescent currents despite employing sleep modes. The linear regulators were a poor choice as they dissipate too -much heat. The fingerprint sensor and the servo draw 13.8 mA (3.3 V) and 4.6 mA -(5 V) respectively, as long as they are connected to the power supply. +much heat. The fingerprint sensor and the servo draw 13.8mA (3.3V) and 4.6mA +(5V) respectively, as long as they are connected to the power supply. -Although the circuit didn't draw more than 200 mA without a load, the servo -under load could draw up to 600 mA. I'm sailing too close to the wind with 0.3 -mm copper traces. Instead, 0.4 mm wide 2 oz/ft<sup>2</sup> traces would have -been safer. +Although the circuit didn't draw more than 200mA without a load, the servo +under load could draw up to 600mA. I'm sailing too close to the wind with 0.3mm +copper traces. Instead, 0.4mm wide 2oz/ft<sup>2</sup> traces would have been +safer. I'm working on improving the design to reduce idle current consumption and extend the battery life. Despite its deficiencies, this was my first PCB |