Power calcs and data sheet reading for pinouts + required external circuitry for clock modulator IC. MCU pinouts underway. Pictures below.
On schedule!
Next week: Finish pinouts, start layout
Gleb’s Status Report for 9/27/2025
- Primarily busy with clock architecture + design presentation
- We need to supply synchronized clocks to the EPC660 sensor IC and the LED driver. The clocks should be synchronized, with the sensor clock being double the frequency of the modulation clock. Furthermore, the phase delay should be adjustable to enable to allow us to run the sensor in the imaging mode, and to allow us to compensate signal propagation delay between boards.
- I have explored different discrete clock generation solutions, while Sid has looked into clock generation on STM32 directly. For instance, I have looked into using an external PLL chip or a flipflop frequency divider. Additionally, I have explored adding a quadrature signal and using VGAs to enable the phase shifting.
- Our final solution is using Si5338 four-channel clock generation IC. It supports both single-ended and LVDS signalling, which is convenient for using it with EPC660 as well as the modulation driver. The frequency and phase delays will be configured from the MCU via I2C.
- I have also imported LED and driver models into PSPICE.
- I will be running simulations and designing the LED PCB next week.
Sid’s Status Report for 9/20/25
This week, we did our proposal presentations. I spent last weekend making a Gantt chart for our proposal and determining specific tasks for all of us. This week, I started autogenerating firmware using STM32CubeMX. We tested out the clock generation functionality with an oscilloscope with a Nucleo board. We were able to also verify that two clocks on two different GPIO pins were synchronized without phase delay.
Next week, I plan on starting the DCMI firmware and setting up the DMA pipeline from the peripheral to memory.
Claire’s Status Report for 9/20
09/20
Component, headers, and MCU selection complete after confirming compatibility on data sheets. Figured out powering board / supplies needed as well as voltage step-down circuitry. Notes below.
Digital
3.3V VDDIO for high speed IO pins like MODCLK
Lots of switching noise, supply wires and layers must be carefully designed and isolated in a separate supply island on the PCB
-> step down to 1.8V for VDD VDDPLL
Analog
+5V for internal analog circuits
External Power Supply (for now)
+10V VDDPXH pixel field circuit
-10V VBS biasing pixel field
Progress is on schedule!
Next week: Layout PCB through Altium Designer
Gleb Ryabtsev’s Status Report for 9/20
- Researched various high-power high-frequency LED driver configurations.
- Settled on EPC21603, a 100MHz laser diode driver.
- Prepared P-Spice models and environment but haven’t ran comprehensive simulations yet.
- My progress is on track. We are planning to spend the next week running the P-Spice simulation and doing some more testing on an STM32 breakout board. Once those steps are complete, we can proceed with designing the PCBs.
Team Status Report for 9/20
- Our project relies heavily on custom high-speed mixed-signal PCB design. Issues with the PCB performance can jeopardize the success of our project. We are taking steps to de-risk:
- We are running P-Spice simulations of the analog circuitry to verify the high-frequency behavior (at steady state).
- We are doing test on an STM32 F7 eval board to make sure that we can generate synchronized modulation clocks for the LED and the sensor chip. See the picture below.
- We haven’t changed the system design, but we have worked out the specifics of the LED modulator circuit.
- No schedule updates.
Introduction and Project Summary
Introducing: The Illuminator. We are developing an underwater, visible light time-of-flight camera system for TartanAUV autonomous vehicles to overcome the limitations of traditional LiDAR (which fails underwater due to infrared light absorption) and existing alternatives like low-resolution sonar and feature-dependent stereo cameras. The system consists of two PCB modules – an illumination module with a high-power LED driven at ~40MHz PWM frequency and a sensing module featuring an EPC660 image sensor communicating with an STM32F7 MCU – designed to identify submerged objects around 4-16 feet while filtering out backscatter, turbidity, and overcoming low signal-to-noise ratios in underwater environments. Operating at 5 watts via Power over Ethernet with integrated filtering and desktop visualization software, the system will undergo progressive testing from mock protocols to air-based trials before final underwater validation.