ToF laser device

[mr_byte31]

I watched this video and I am excited to build similar device  : https://youtu.be/y7pbxEbqnVI

I want to build the project under 100 euros.

Below are the components that were figured out in the video :

• MAX913 : Single/Dual, Ultra-Fast, Low-Power Precision TTL Comparators
• EPM3064 : Altera CPLD capable to work up to 227 MHz (I may use XC2C64 but not certain yet)
• NE555:  it maybe used for laser modulation as seen on oscilliscope
• Avalanche Photodiode
• IR laser diode

I believe that MAX913 will generate a pulse that indicate the time difference between transmitted signal and received one.
The CPLD maybe used to read the duration of the generated pulse from MAX913.
do you think my guesses are correct?

Most online stores indicate out of stock components and I can't find oscillator for the CPLD to work at 200 MHZ.
I was thinking to overclock Pi Pico to generate a fast clock but I am not convienced it shall be a good option.

do you know a cheap oscillator operating at 200 MHz?

[Old_but_Alive]

STMicro have a very good selection of ToF sensors

https://www.st.com/en/imaging-and-photonics-solutions/time-of-flight-sensors.html

[mr_byte31]

STMicro have a very good selection of ToF sensors

https://www.st.com/en/imaging-and-photonics-solutions/time-of-flight-sensors.html

I know about that and their solutions are in range of 5m or even less.

The device I want to build has range of 1500m

[titi]

If you need a good precision with the frequency, you can find cheap 200MHz TCXO 0.1ppm on AliExpress (by Example) for near 12€ like this one.

An other solution is to use a XTAL 25 MHz and use an ICS511 (Multiplier) configured in Mult x8 (near 3€ at AliExpress).

Best Regards.

[mr_byte31]

I found the TCXO and it is quite expense option. I had Pi Pico on the shelf and I was thinking to overclock it to 200 MHz to clock the CPLD. this will be much cheaper than the TCXO.

The XTAL 25MHz + ICS511 shall be a perfect option. The price of 10 pieces of ICS511 is almost 3 euros. This is definitly good price.

[token0]

I know about that and their solutions are in range of 5m or even less.

The device I want to build has range of 1500m

I believe you need an avalanche diode with separate infrared laser instead of ToF device for such long distance. Also some infrared optics.

[M38]

Hi,

you can use a TDC7200 to get the time between the emssion of the pulse and the reception. It's resolution is 55ps.
https://www.ti.com/product/TDC7200

[Catcatcat]

Hi,

you can use a TDC7200 to get the time between the emssion of the pulse and the reception. It's resolution is 55ps.
https://www.ti.com/product/TDC7200

Good solution and low cost only $1.5

https://jlcpcb.com/parts/componentSearch?searchTxt=TDC7200

[Magnox]

Agreed, the TDC7200 is a great chip for things like this. I used one in my GPSDO to measure the phase offset of my derived PPS from the true second start, followed by a Maxim delay line and clock pulse tweaking to adjust it.

The TDC7200 can measure total times from 12ns up to 8ms.

[damo1023]

As one of the previous answers - check out ST's ToF sensors. You can buy them cheap at Ebay. Communication is easy thru I2C. ST has even 2D depth sensor, looks like nice one to toy with.

[mr_byte31]

Thx, TDC7200 seems as a good option.

I was planning to use TDC-GP21 , it is very popular and I can buy it as a board from Aliexpress.