Servers by jDrones

What do you know about GPS L5 recievers?

Does anyone know where to obtain BCM47755 chips or products containing the chip? I’ve checked the usual suspects (mouser, digikey, etc) with no success - although mouser does have an “alert me when available” product page for BCM47755.

Mouser does have a listing for Quactel LC79D eval boards that include BCM47755 but they don’t seem to actually be for sale.

Has anyone seen these things in the wild? Are there any other chips that will receive the new (ok, just newish) L5 GPS signals?

There’s been some testing of Allystar L5 modules (mixed results), and I have a Quactel L89 that I’ll check out at some stage, but we don’t have the Broadcom chipset as yet. There’ll be a pretty comprehensive write up of gps testing published shortly.

1 Like

I was able to find them for backorder on mouser. First parts should be shipping my way on 3/1.

LC79DAEK is the dev board. Mouser only ordered 2 of them? I bought one, and it’s shipping to me on 3/1. https://www.mouser.com/ProductDetail/277-LC79DAEK/

LC79DAMD is the module. They won’t ship out until 3/26 and mouser ordered 249 of them. https://www.mouser.com/ProductDetail/277-LC79DAMD/

Interestingly, I just noticed you’re using LC89 series and I stumbled on LC79 series. I’ve not yet figured out exactly what the difference is. Wish they had a little comparison chart somewhere.

L89 Spec sheet: https://www.mouser.com/datasheet/2/1052/Quectel_L89_GNSS_Specification_V1_1-1829989.pdf

LC79D Spec sheet: https://www.quectel.com/UploadFile/Product/Quectel_LC79D_GNSS_Specification_V1.1.pdf

79d is physically smaller, uses less power and has greater accuracy (<1.2m vs <1.8m). I think it’s the better part, but it’s hard to tell. Formatting between the two spec sheets is slightly different making comparison hard to do. Not n–p hard, but still hard.

ST and Ublox both make a dual band chip, but the ublox boards are ~200.00, ST boards are ~400 while the Quectel models are ~20.00 (50 for dev kit).

I have used these with good results: http://navspark.mybigcommerce.com/ns-hp-gn2-px1122r-multi-band-quad-gnss-rtk-breakout-board

Those who are using the new systems, are you also using RTK? If so, are you on a public RTK or do you have your own base station?

FYI: Mouser has some of these in stock now. The LC79 products from Quectel do work for multi band reception. The documentation included on the thumb drive in the devkit omits the new LC79 chips, so you’ll have to ask quectel to set you up an account so you can download the docs from their website… no idea why they’d password protect datasheets and user manuals in the first place, but they did.

Edit: nevermind… guess they only had a few. The page now says out of stock, expected 3/26.

Servers by jDrones