Arduino Nano vs Uno: Same Chip, Different Build
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Arduino Nano vs Uno: Same Chip, Different Build
Quick answer: The Nano and Uno both run the same ATmega328P at the same 16MHz, and share an identical digital pin map — but the Nano breaks out 8 analog pins (A0-A7) against the Uno's 6, and plugs directly into a breadboard where the Uno needs jumper wires. Nano clones start around Rs.210.
Written and fact-checked by Compoden's engineering team, India. Every spec and price below is read from our live catalogue record for the exact part named. Published 19 August 2026 · Last updated 19 August 2026.
Ask what's different between a Nano and an Uno and most answers stop at "the Nano is smaller." That's true, but the genuinely interesting differences sit underneath that observation: the exact same microcontroller, exposed through two differently designed boards, ends up with a different total pin count, a different power-input story, and a completely different relationship with a breadboard.
| Spec | Nano (CH340 clone) | Nano (official, A000005) | Uno (CH340G clone) |
|---|---|---|---|
| Price (India, COD) | Rs.210–250 | Rs.1,860 | Rs.230 |
| MCU | ATmega328P, 16MHz | ATmega328P, 16MHz | ATmega328P, 16MHz |
| Flash / RAM | 32KB / 2KB | 32KB / 2KB | 32KB / 2KB |
| Digital pins | 14 (6 PWM) | 14 (6 PWM) | 14 (6 PWM) |
| Analog pins | 8 (A0-A7) | 8 (A0-A7) | 6 (A0-A5) |
| USB connector | Micro-USB or Type-C | Mini-B (FT232RL) | USB-B (CH340G) |
| Breadboard-friendly | Yes | Yes | No |
| DC barrel jack | No — USB or VIN pin only | No — USB or VIN pin only | Yes, plus USB |
Verdict in one line: same brain, different body — pick the Nano for breadboard prototyping and the extra two analog pins, the Uno for shield compatibility and a sturdier USB connector.
Is the Nano really "the same chip" as the Uno?
Yes, down to the pin map. Both boards run an ATmega328P at 16MHz with 32KB flash and 2KB RAM, and our records confirm the digital pins carry identical roles on both boards — D0/D1 are UART, D2/D3 are the two interrupt pins, D3/D5/D6/D9/D10/D11 are the six PWM pins, D10-D13 are SPI. A sketch written for one runs unmodified on the other, because the underlying pin logic genuinely is the same chip wearing two different boards.
So what's actually different?
The analog side, and it's a real hardware difference, not a labelling one. Our Nano records confirm 8 analog pins, A0 through A7 — and A6/A7 are explicitly analog, input_only in the pin data, meaning they can read a voltage but cannot be used as digital pins at all. The Uno's own record, and its own pinout guide on this site, stops at A0-A5. The ATmega328P chip itself has those extra two analog channels; the Nano's smaller board breaks them out, and the Uno's board simply doesn't.
The reason runs one level deeper than board layout, and it's well-documented Atmel/Microchip hardware knowledge rather than something our own catalogue records state directly: the Nano uses the ATmega328P in its 32-pin TQFP surface-mount package, which physically has ADC6 and ADC7 pins on the silicon package itself. The Uno uses the same chip in the older 28-pin DIP package, which has no equivalent pins at all — not "unconnected," genuinely absent from that package's pinout. So this isn't a case of the Uno's designers choosing not to wire something up; the through-hole chip on an Uno could not expose A6/A7 even if someone wanted to add the traces.
Why does the Nano plug into a breadboard and the Uno doesn't?
Board shape, not electronics. The Nano's pins run down both long edges on standard 0.1" spacing narrow enough to straddle a breadboard's centre channel, so it plugs in directly like any other DIP component. The Uno is deliberately wider and carries female shield headers instead, designed for stacking add-on shields rather than breadboard use — our own Uno record calls this its natural role. Wanting to breadboard an Uno anyway means jumper wires to every pin you need; a Nano just plugs straight in.
Why does neither Nano have a DC barrel jack?
Size. Both Nano records confirm power comes from USB or the VIN pin only, with no barrel jack broken out — there simply isn't board space for one on a board this small. The Uno keeps its jack because the extra width that makes it shield-compatible also leaves room for it. Practically, a battery-powered Nano project needs its supply wired to VIN and GND directly, rather than a plug-and-play jack connector.
Which USB connector should you actually want?
Depends which Nano. The official Arduino Nano uses a Mini-B connector with an FT232RL USB-serial chip — our record flags "FT232RL counterfeit risk" and "USB connector fragile" as known issues, since Mini-B is an older, less mechanically robust connector than what's common today. The CH340 clones instead offer Micro-USB or, on newer stock, USB Type-C — cheaper, and Type-C in particular is a sturdier, reversible connector most people already have a cable for. The tradeoff is the CH340 chip itself, whose own record notes "CH340 driver may need manual install on some OS," a one-time setup step the official board's FTDI chip usually skips. One more CH340 clone quirk worth knowing before your first upload, again general Arduino IDE knowledge rather than a catalogue figure: many CH340 Nano clones ship with an older bootloader than the official board expects, and a failed upload with an "avrdude: stk500_recv(): programmer is not responding" error is often fixed by selecting "ATmega328P (Old Bootloader)" under Tools > Processor in the IDE, rather than a wiring or driver problem at all.
What actually goes wrong on each board?
Overlapping in one place, different everywhere else. Both a Nano CH340 clone and the official Nano share the same underlying weak point our records both flag: "voltage regulator overheating" under sustained load, since neither board has much room for heat to dissipate from its onboard 5V regulator. Past that, the failure patterns diverge by build. The CH340 clone's own record adds "no reverse polarity protection on Vin" — plug external power in backwards and there's nothing between that mistake and the chip, unlike boards with a protection diode. The official Nano's record instead flags "brownouts under load" and a "3.3V output limited to 50 mA," the same 3.3V ceiling our Uno pinout guide covers on that board — not enough current for most 3.3V sensor modules expecting their own supply. Neither failure is common on a lightly-loaded hobby build, but both are worth knowing before adding a motor or a power-hungry 3.3V module directly to either board's own rails.
Which real projects actually favour one board over the other?
Shield compatibility settles it more often than raw specs do. A build using an off-the-shelf LCD keypad shield, an Ethernet shield, or a motor shield needs the Uno's header layout — those shields are physically designed to stack onto the Uno's wider board, and a Nano has no equivalent stacking system at all. Conversely, a permanent breadboard build, a project going into a tight enclosure, or anything where two extra analog inputs matter (reading more sensors than the Uno's six analog pins allow without an external multiplexer) points at the Nano. Neither board is more "capable" in a general sense; the decision is almost entirely about the physical shape of the rest of the build.
Which board should you actually buy?
For breadboard prototyping, sensor testing, or any build where board size matters, the Nano R3 CH340 (with USB cable) (Rs.250) — cheapest way to get a Nano working out of the box. Want the newer Type-C connector instead? The Nano R3 CH340 Type-C (Rs.210). Need guaranteed driver-free setup and official support? The Official Arduino Nano A000005 (Rs.1,860). For shield compatibility instead of breadboard use, the Arduino Uno R3 CH340G (Rs.230) covered in our full Uno pinout guide. All available cash on delivery across India.
What should you read next?
Comparing the Uno side more closely? Our Arduino Uno pinout reference covers its full pin map and current budget. Choosing between an ESP32 and either of these instead? See ESP32 vs Arduino Uno.
Not sure which board fits your build? Open Soldr, describe your project and how much space you have, and it will pick the board.
Frequently asked questions
Arduino Nano aur Uno mein kya farak hai?
Dono mein same ATmega328P chip hai, 16MHz par, same digital pins ke saath. Farak yeh hai: Nano mein 8 analog pins hain (A0-A7), Uno mein sirf 6 (A0-A5). Nano breadboard mein seedha lag jaata hai, Uno nahi lagta - uske liye jumper wires chahiye. Nano mein DC jack nahi hota, sirf USB ya VIN pin se power milta hai, jabki Uno mein dono hote hain.
Can I run the same code on a Nano and an Uno?
Yes, in almost all cases. Our records confirm both boards' digital pins carry identical roles - same PWM pins, same interrupt pins, same SPI pins. A sketch that only uses D0-D13 and doesn't rely on the Uno's extra barrel-jack power path will run unmodified on either board.
Why does the Nano have 8 analog pins when the Uno only has 6?
Both boards use the same ATmega328P chip, which does have 8 analog input channels on the silicon. Our Nano records confirm all 8 are broken out (A0-A7, with A6/A7 explicitly analog-input-only). The Uno's board simply doesn't wire out those last two channels, stopping at A0-A5.
Should I buy the official Nano or a CH340 clone?
The CH340 clone for most projects - our record notes the CH340 driver may need a one-time manual install on some operating systems, but it's otherwise identical in capability and far cheaper (from Rs.210 vs Rs.1,860). The official board's FTDI chip skips that driver step and avoids the Mini-B connector's fragility our own record flags as a known issue on the official unit, which matters more for a board you'll plug and unplug often.
What is the price of an Arduino Nano in India?
At Compoden, Nano R3 CH340 clones start at Rs.210 (Type-C, soldered) and go up to Rs.250 (Micro-USB with cable included). The Official Arduino Nano A000005 is Rs.1,860. All available with cash on delivery across India. Prices checked August 2026.