Adafruit RS-232 Full Pinout Level-Shifter Breakout

SKU: ADA5988 Brand: Adafruit

If you want to interface with telco, retro, or industrial equipment, you'll probably run into RS-232 interfaces. The Adafruit RS232 Full-Pinout...

$14.20 AUD, inc GST

$12.91 AUD, exc GST

In stock, ships same business day if ordered before 2PM
Fastest delivery: Tomorrow* Disclaimer:
The shipping address needs to be in the AusPost next day network and eParcel Express is chosen during checkout. On rare occasions, orders may be delayed by up to one business day due to AusPost pickup timings or for order verifications.

Quantity Discounts:

10-25 $12.39 (exc GST)
25+ $12.01 (exc GST)

If you want to interface with telco, retro, or industrial equipment, you'll probably run into RS-232 interfaces. The Adafruit RS232 Full-Pinout Breakout with 8 Channels of UART to RS-232 Level Shifters is your friend in such cases. It gives you 5 input and 3 output channels of level shifting and takes care of the high/negative voltage generation all in a low-cost breakout board. We use the trusty MAX3243 from TI, a classic chip part of the MAX232 lineage, so you know it will work great for all your RS-232 needs, up to 250Kbps.

RS-232 is what Adafruit had before USB: a 9- or 25-pin D-Sub connector that allowed data plus flow control lines. Many folks may remember these interfaces were used for mice, modems, barcode scanners, teletypes, and more. We still find devices sold with RS-232 ports, although many folks use a USB to RS-232 adapter these days.

If you want to use a microcontroller or microcomputer to chat with an RS-232, then thankfully, all you need is a serial port / UART (something just about any microcontroller has) and a level shifter. The level shifter is required because while most UARTs are 0-3.3V or 0-5V logic level, RS-232 requires +-6 to +-10V, yep the signal voltage goes negative! That means a specialized shifter is required to generate extra high and low voltages and safely convert the logic levels.

Sure you could buy a raw MAX232 chip and wire up the necessary capacitors, but this board does it all for you and even comes with a DE-9 connector for plugging in directly into your 'client' device. It can run on 3.3V power and logic, which many older chips can't do. It also can do all 8 data pins, so you can use all of the flow control signals like RTS, CTS, DTR, DSR, DCD and RI.

They also include two separate lines from the MAX3243: 'Valid' and 'Off'. The Valid line output will have logic level high when the chip detects signal voltages from the device its plugged into. So you can use it as a 'connection made' signal. There's also the Off pin, which when set to logic high by the microcontroller will tri-state all the pins for power reduction.

This breakout comes fully assembled with a UART side for low-voltage power/logic level, and a DE-9F RS-232 side for high-voltage signals. They also include some header so you can solder to a breadboard in a few minutes.

Technical Details

MAX3423 Features:

Operates With 3-V to 5.5-V VCC Supply
Single-Chip and Single-Supply Interface for IBM™ PC/AT™ Serial Port
RS-232 Bus-Pin ESD Protection of ±15 kV Using Human-Body Model (HBM)
Meets or Exceeds the Requirements of TIA/EIA-232-F and ITU V.28 Standards
Three Drivers and Five Receivers
Operates Up To 250 kbit/s
Low Active Current: 300 µA Typical
Low Standby Current: 1 µA Typical
Accepts 5-V Logic Input With 3.3-V Supply
Serial-Mouse Driveability

Product Dimensions: 33.6mm x 32.0mm x 14.1mm / 1.3" x 1.3" x 0.6"

Product Weight: 11.2g / 0.4oz

This product is listed in:

Breakouts & Modules>RS232

Product Comments

Start the conversation

Exact shipping can be calculated on the view cart page (no login required).

Products that weigh more than 0.5 KG may cost more than what's shown (for example, test equipment, machines, >500mL liquids, etc).

We deliver Australia-wide with these options (depends on the final destination - you can get a quote on the view cart page):

$3+ for Stamped Mail (typically 10+ business days, not tracked, only available on selected small items)
$7+ for Standard Post (typically 6+ business days, tracked)
$11+ for Express Post (typically 2+ business days, tracked)
Pickup - Free! Only available to customers who live in the Newcastle region (must order online and only pickup after we email to notify you the order is ready). Orders placed after 2PM may not be ready until the following business day.

Non-metro addresses in WA, NT, SA & TAS can take 2+ days in addition to the above information.

Some batteries (such as LiPo) can't be shipped by Air. During checkout, Express Post and International Methods will not be an option if you have that type of battery in your shopping cart.

International Orders - the following rates are for New Zealand and will vary for other countries:

$12+ for Pack and Track (3+ days, tracked)
$16+ for Express International (2-5 days, tracked)

If you order lots of gear, the postage amount will increase based on the weight of your order.

Our physical address (here's a PDF which includes other key business details):

Unit 18, 132 Garden Grove Parade
Adamstown
NSW, 2289
Australia

Take a look at our customer service page if you have other questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.

Have a product question? We're here to help!