laptop wifi module - Page 1
Forum section: electronics / beginners

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 09:30:00 am
content: i am going to make external wifi module, but need pinout to connect usb power supply and data lines. help please!

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 09:34:07 am
content: there is a picture

author: Gyro
author_rank: Super Contributor
timestamp: March 16, 2021, 10:35:43 am
content: I think those modules are PCI interface, not USB.

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 10:47:46 am
content: i think to reduce usb voltage with 3.3v linear voltage regulator.

author: Gyro
author_rank: Super Contributor
timestamp: March 16, 2021, 10:54:32 am
content: You can't just connect USB data signals to a PCI interface device.

author: Nominal Animal
author_rank: Super Contributor
timestamp: March 16, 2021, 11:52:00 am
content: You have a mini-PCIe module. The mini-PCIe connector has both PCIe and USB interfaces. Usually, the WiFi modules use the PCIe interface, and WWAN (3G/4G/5G/LTE wireless modems) the USB interface. As far as I know, ATH-AR5BXB63 uses the PCIe interface, not the USB one.You can find lots of different mini-PCIe-USB adapters on eBay and elsewhere, described as WWAN USB adapters. However, because most WWAN adapters actually prefer a higher than 3.3V voltage – 3.6 to 4.0 V is typical –, you should check their voltage before use. You can find the pinout for examplehereandhere(PCI Express Mini Card section). Note that you want to avoid the ones with a voltage regulator, as the regulator can get quite hot: if the module consumes say 200mA at 3.3V (0.66W), the regulator drops 1.7V at 200mA – an additional 0.34W. You want one with a DC-DC converter; recognizable from the inductor (SMD coil) close to an IC. Other than the voltage conversion, these adapters only have passives (some bypass capacitors), no logic at all.I have a few of these, because I use a WWAN 4G/LTE modem (Huawei ME909s-120).

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 01:00:48 pm
content: Quote from: Nominal Animal on March 16, 2021, 11:52:00 amgreat! thank you very much.

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 01:09:05 pm
content: which pin is for power input (+) ? I know GND is for negative voltage (-). pin 36 is for USB_D- and pin 38 is for USB_D+.is power (+) pin 2, 24 or 52?

author: Nominal Animal
author_rank: Super Contributor
timestamp: March 16, 2021, 01:23:10 pm
content: On a typical adapter for USB, you haveGND on pins 9, 35, 433.3V on pins 2, 24, 52 (but may be higher for dedicated modem adapters, since they prefer a higher voltage)USB 2.0 D- on pin 36 and D+ on pin 38SIM card connected to pins 8 (SIM_Vcc), 10 (SIM_I/O), 12 (SIM_CLK), 14 (SIM_RST), and 16 (SIM_VPP)See e.g. Markus Virtanen's designs at EasyEda:v1.0andv2.1, but note that he uses a voltage regulator, whereas I firmly recommend an efficient DC-DC converter instead. Me no EE, though, just a hobbyist.

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 01:27:46 pm
content: Quote from: Nominal Animal on March 16, 2021, 01:23:10 pmthanks, now I can experiment with dc-dc step down converter, first with 3.3v input voltage. hopefully it will work.

author: kimlanbu
author_rank: Newbie
timestamp: March 16, 2021, 01:34:28 pm
content: I suggest you to use ESP32 instead. Lots of libraries and examples codes avaliable.

author: perieanuo
author_rank: Frequent Contributor
timestamp: March 16, 2021, 01:52:50 pm
content: https://pinoutguide.com/Slots/mini_pcie_pinout.shtmlhttps://www.instructables.com/Running-mini-PCI-e-3G-card-with-USB-mini-PCI-e-t/

author: Nominal Animal
author_rank: Super Contributor
timestamp: March 16, 2021, 02:23:52 pm
content: Quote from: archil on March 16, 2021, 01:27:46 pmAs I mentioned, I do believe ATH-AR5BXB63 is PCIe-only, and does not use the USB data lines, so I do not believe it will work.There are lots of USB-connected WiFi chips, though, for example RTL8822BU. In my opinion, it would make more sense to find an existing (dual band?) USB WiFi dongle already supported in mainline Linux ($10 - $30 USD), and if necessary, tear it down and use its innards in your own design.