Light Meter Board First Attempt

[streetrailpark]

Hello all! Please bear with me. I'm a photographer with some camera repair experience and i'm trying to diy a meter solution for an old camera. It's bringing together a lot of fields including cad design, cnc machining, pcb design and programming. As such I've been trying to fast track my blind spots with ai (perhaps much to your chagrin). This is my first pcb design attempt and I'm hoping for some feedback on its functionality and reliability as an electric system, any help would be much appreciated. The board's small dimensions are necessitated by the space into which it must fit.

The design is using a 3v cr2016 cell battery and a 4 pin stepper motor, powering a small indicator needle. It has two drivers wired to the motor, each driver having a 10uf capacitor close to the vm pin. The chip is an atTiny84v running the drivers, an adafruit 19 light meter and a tactile switch that wakes the chip for a short time upon pressing. There is a 10uf capacitor between the battery line and the rest of the board. There are 100nf capacitors wired to the vcc(#8) pins of the motor drivers. There is a 10ko resistor on the attiny reset pin.  There is a 10k potentiometer wired to an attiny pin that is going to adjust iso via a dial mated to the trimmer. The bottom of the pcb has a few traces and a large copper pour, also the pos and neg pads that will have battery contacts soldered on. I really have no idea if what I've made is functional or complete trash but I'm hoping its closer to the former.

Here are some screenshots of the schematic as well as the top and bottom of the pbc.

[Psi]

You have some errors where you think you have connected things on the schematic but they are not actually connected.

Check out R1 top pad on the PCB, and Pin4 on the MCU which are unconnected and shouldn't be.

You need to sort out the connection on the schematic first.
Expand things so they are less bunched up with lots of joins and overlaps.

You currently have things that overlap in odd ways, and wires that move back on themselves, and on other traces, and wire joins too close to pins and other things.

Then when you get the schematic good move on to a PCB tidy up.
Route tracks to the center of pads.
Keep tracks away from other tracks where possible.

[Terry Bites]

I think that you could keep nearly all routing except ground on the component side and have an uninterrupted ground-plane underneath.
Its always worth spending time on placement and routing retries. It is educational.

Can CR2016 batteries supply the motor current required?
These batteries have about 80 ohms of internal resistance when fresh.
Stack up 3 of them and that's 240 ohms!  CR2016_Data_sheet_e.pdf (641.64 kB - downloaded 2 times.)
Worse still, this battery can only mange 5-15mA even under pulsed conditions.
Vcc could sag causing erratic behaviour in the attiny and the drivers.
Driver bulk caps could be made larger to help mitigate this, but its not guaranteed to work.
Route driver power Vcc and digital Vcc separately and only join them together at the power entry point.
Spikes from the driver/ motor could find their way into the attiny digital IO's causing more erratic behaviour.
The driver IC has internal freewheel diodes but I'd still add external diodes. They're a lot cheaper to replace than the IC. eg BAS40BRW.

A little advice. You need to work on creating more easily readable schematics.
Its very time consuming for others to unravel spaghetti.
Layout from left to right. Inputs on the left, outputs on the right.
There is no need to wire all grounds and power supplies together.
Make use of Global Labels (global signals) in the schematic.

A side note. Why not drive analog meters with PWM from the attiny? They typically only need 50 microamps for full scale.
You could remove the meter movements from their cases to repurpose them.